# Engine swap



## aem394 (Apr 14, 2019)

Hi, I am considering installing a small block chevy motor in my 66 LeMans. Has anyone done this? It’s a four speed car, any advice would be appreciated. Thanks


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## 1966GT0 (Jan 17, 2016)

I did this swap in my 66 GTO so you should be pretty much the same. I'm sure I won't remember everything but one big thing that will always help is when looking for a part go with 1966 Chevelle. Basically the same frame and such. 1) Buy a set of small block chevy motor mounts. 2) The starter will be on the passenger side, if you are stock setup you will probably need to mount the battery on the passenger side like a Chevelle. you can order that battery tray and drill one hole in the inner fender and it fits exact, 3) fuel line will be coming down the wrong side of the car, several ways to overcome this you can decide which is best for you. 4) Trans mount and driveshaft from pontiac setup all worked but you will need a chevy bellhousing and fork. Hope this helps, I can say this worked for me for many personal and future plan reasons but will tell you it's not just bolt-in. Don't rule out finding a Pontiac engine and paying a little more up front. It may save you time and money in the long run. It can be done, isn't too terribly tough, but certainly isn't bolt-in. Good luck with however you go bottom line is you gotta have a motor to enjoy it!


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## bigD (Jul 21, 2016)

"...Don't rule out finding a Pontiac engine and paying a little more up front..."

^^^^^^^^^^^^THIS^^^^^^^^^^^^^^^

There are still a few of us old timers who think the old Pontiacs, especially the A-bodies should have Pontiac power, or sell the car to someone else & buy a Chevy.

I can't see any reason to own a Pontiac A-body & put a Chevy engine in it. I understand that a cheap Chevy engine is cheaper than a Pontiac engine. But, if your budget is so low that you can't afford even a low budget Pontiac engine, then maybe that Pontiac is not the right car for you.

This is not a personal attack on you, or anyone in particular. It's just a generalization, and is my personal opinion, and probably the opinion of thousands of other long time Pontiac lovers.


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## 1968gto421 (Mar 28, 2014)

Both here and in the PY forum yiu see folks almost giving away complete and frequently running Pontiac 350 engines. This may be the easiest way to go and least expensive. Check the ads on this forum: 
https://www.gtoforum.com/f49/

And also on the PY Pontiac forum:
BUY, SELL, TRADE Classic PONTIAC "PARTS" - PY Online Forums

Of course there is always the E-bay ads in which to find engines.

(I will be stoned by other members for this, but the PY Pontiac forum has a section if you continue in your SBC longings, here is the site:
Non Pontiac Motors in Pontiacs - PY Online Forums

Anyway good luck with your '66 LeMans!


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## 67goat (Oct 27, 2006)

If you had the time, know how and tools, you could swap in about any engine you wanted. However opening the hood of the LeMans only to see a small block really cheapens the car IMO and makes you start to wonder what other corners were cut on the car in order to get it running. Reason I say cheapens is because Chevy parts are slightly cheaper than Pontiac parts and Chevy's have always been considered GM's "entry level" car or a car for those that are "budget challenged" so if you see the "cheap" engine option in a Pontiac you start to wonder what other "cheap" parts the owner decided to use or whether the owner skipped other maintenance items. 30 years ago when there were limited cylinder head options you could potentially make an argument why to switch engines but that is not really the case any more. With the aftermarket engine parts, including complete Pontiac engine blocks, intakes, fuel delivery, etc. etc. that are readily available today, you can make almost any engine perform the way you want it to. Don't believe me - go to your local dragstrip and look at what all the folks are running under their hoods nowadays and you'd be quite amazed. Stick with the Pontiac engine and not only will your resale value be better but if you use a good Pontiac engine builder (there are several good ones in this country) you should be able to get both the performance and temperament of the engine that you seek.


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## dd68gto (Nov 14, 2012)

67goat said:


> If you had the time, know how and tools, you could swap in about any engine you wanted. However opening the hood of the LeMans only to see a small block really cheapens the car IMO and makes you start to wonder what other corners were cut on the car in order to get it running. Reason I say cheapens is because Chevy parts are slightly cheaper than Pontiac parts and Chevy's have always been considered GM's "entry level" car or a car for those that are "budget challenged" so if you see the "cheap" engine option in a Pontiac you start to wonder what other "cheap" parts the owner decided to use or whether the owner skipped other maintenance items. 30 years ago when there were limited cylinder head options you could potentially make an argument why to switch engines but that is not really the case any more. With the aftermarket engine parts, including complete Pontiac engine blocks, intakes, fuel delivery, etc. etc. that are readily available today, you can make almost any engine perform the way you want it to. Don't believe me - go to your local dragstrip and look at what all the folks are running under their hoods nowadays and you'd be quite amazed. Stick with the Pontiac engine and not only will your resale value be better but if you use a good Pontiac engine builder (there are several good ones in this country) you should be able to get both the performance and temperament of the engine that you seek.


You will find few here on this site or PZy that will want you to make that swap. It's very easy and will save you money in long run. Pontiac motor are becoming hard to find and you can get a crate 350 for 1/2 the price. I am a long time old Pontiac owner but I would rather see a Pontiac on road with a chevy motor than sitting in a back yard rusting away . Best luck and hope you change your mind but I do understand why you would do it Doug


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## dd68gto (Nov 14, 2012)

dd68gto said:


> 67goat said:
> 
> 
> > If you had the time, know how and tools, you could swap in about any engine you wanted. However opening the hood of the LeMans only to see a small block really cheapens the car IMO and makes you start to wonder what other corners were cut on the car in order to get it running. Reason I say cheapens is because Chevy parts are slightly cheaper than Pontiac parts and Chevy's have always been considered GM's "entry level" car or a car for those that are "budget challenged" so if you see the "cheap" engine option in a Pontiac you start to wonder what other "cheap" parts the owner decided to use or whether the owner skipped other maintenance items. 30 years ago when there were limited cylinder head options you could potentially make an argument why to switch engines but that is not really the case any more. With the aftermarket engine parts, including complete Pontiac engine blocks, intakes, fuel delivery, etc. etc. that are readily available today, you can make almost any engine perform the way you want it to. Don't believe me - go to your local dragstrip and look at what all the folks are running under their hoods nowadays and you'd be quite amazed. Stick with the Pontiac engine and not only will your resale value be better but if you use a good Pontiac engine builder (there are several good ones in this country) you should be able to get both the performance and temperament of the engine that you seek.
> ...


 test


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## bigD (Jul 21, 2016)

"...I would rather see a Pontiac on road with a chevy motor than sitting in a back yard rusting away.."


If a guy is gonna put a Chevy motor in an old Pontiac A-body, I'd rather see him sell that Pontiac to someone who would use a Pontiac motor. Then the Chevy motor guy could take the money from the sale of the Pontiac and buy himself a Chevy vehicle and a Chevy engine for it. 

Thru the years, and I've seen quite a few now, I've always been very disgusted to see a decent lookin Pontiac, only to look under the hood & see a Chevy engine. There is a real nice lookin 1st gen Bird that I've seen at several area car shows. But, as soon as I realized it had a Chevy engine, I was no longer interested in lookin at the car.

Back when I raced a lot, several times guys would see our Pontiacs and would come over & want me to come look at their Pontiac. I'd go over to check it out, only to find a Chevy motor in it. I'd just walk off shaking my head. Was not interested in the car or how quick it was, after seeing the Chevy motor, Just a complete turn off, for me. 

My wife was taking pics of Pontiacs at a show a couple of years back. She saw this nice lookin red '67 Bird, so started takin pics of it. Then we saw the sbc engine in it.  Several of us Pontiac guys tried to talk the owners into changing over to Pontiac power. They seemed agreeable. But, last time I saw it, the sbc engine was still in it. Some guys think sbc, BBC, & LS engines are just fine in old Pontiacs. I'm not one of those guys.


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## 67goat (Oct 27, 2006)

dd68gto said:


> You will find few here on this site or PZy that will want you to make that swap. It's very easy and will save you money in long run. Pontiac motor are becoming hard to find and you can get a crate 350 for 1/2 the price. I am a long time old Pontiac owner but I would rather see a Pontiac on road with a chevy motor than sitting in a back yard rusting away . Best luck and hope you change your mind but I do understand why you would do it Doug


Here is a sample of the "hard to find" Pontiac crate engines (not endorsing any, just posting sample list of options)...plenty more on ebay as well, just take your pick - the ones below are performance engines but you can build for much cheaper if you really want only 350 HP that the Chevy crate engine makes. If you have a "hard" time finding, you must be too lazy to browse the internet. You also forget the cost and time difference of the changes needed to switch engines - that is no surprise considering you were too lazy to browse the internet, so probably too lazy to think the whole project through. That is why when I see a Pontiac with a Chevy engine I walk away because very likely the owner was too lazy to browse for the best options and too lazy to really think it through.

https://www.dcimotorsports.com/services/dci-pontiac-400-stroked-to-455-crate-engine/

Pontiac Performance Crate Engines

https://www.tinindianperformance.com/

https://butlerperformance.com/i-244...01-cu-in-long-block.html?ref=category:1267471

SD Performance- Pontiac Performance Specialists


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## bigD (Jul 21, 2016)

The only reasonably priced good quality Pontiac crate engines I know of are built by Len Williams. And they're about $5000 & up, shipped. 

400 Long Block

455 Long Block

The base brand new 350 sbc long block engine can still be bought for less than $2000 shipped, and has a 3 yr/100k mile warranty. So, there is absolutely no doubt that sbc is the cheap way to go. 

https://www.ebay.com/itm/CHEVROLET-...077173&hash=item43f8d0478b:g:9xUAAOSwXqZbLRmj

https://www.amazon.com/Genuine-GM-1...ords=10067353&qid=1555683489&s=gateway&sr=8-1

Now there are cheaper Pontiac long blocks available. But they are sold by the large volume engine rebuilders, and will have the cheapest parts, like cast rebuilder pistons. Pontiac engine cores are also a problem with the big rebuilders. They most likely won't have the block/heads you want. The block they are likely to have will probably be the weak 500557 block. They do have some sort of warranty. But, if you need to use the warranty, you're out shipping both ways, and will get back the same quality engine you got the 1st time. But, I'm sure there are some out there, somewhere, who have actually got good service from one of these cheap Pontiac engines.

A quick search turned up this site. The best deal I see is a 455 for $2290 + $800 core charge + shipping. But, I doubt they even have a good 455 core in stock. They also show some 400 engines, for about the same price. But, those will probably have the horrible "8 eyebrow" cast rebuilder pistons. And it's likely that the only block they have will be a 500557. I could be wrong. 

http://remanufactured.com/Pontiac_Engines.htm

Here's one that's even cheaper. Description says it has a 7 yr/100k mile warranty & that performance options are avilable. Comes with #98 heads, which are low compression 2-barrel heads, with press-in studs. But, they show that 6X heads are available on 400 engines they sell. So, if you could get them to substitute the 6X heads, then that 455 MIGHT be a decent deal. 

http://www.hiperformer.com/engines/pontiac-firebird-rebuilt_engines-pon_455lb.html

Here's one that's advertised as a Ram Air 3 engine. Nothing about it is RA3, except maybe the cast rods. probably has a 500557 block too. 

http://www.rebuiltcrateengines.com/pontiac-400-gto-ram-air-iii-v8-p-2155.html

Here's another cheap 400 listing. But, you'd likely not get the #96 heads, since a good ready-to-run set could easily cost $800-$1000. 

http://www.rebuiltautoengines.com/pontiac-V8_6.6_400-pon_400lb-engine.html


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## dd68gto (Nov 14, 2012)

I will repeat finding good Pontiac block are getting hard to find. The motors that were listed are 10000 and up.builds That 455 stroker closer to 12000. I think if the OP had that kind of money he wouldn't be looking to swap . If you are lucky to find a nice clean standard bore 400 it will cost you well over 5000 to build . I'm not a chevy guy but please don't tell me that you can't buy very good chevy motors for much less. And I would not spend 5000 plus unless it is s standard bore. Doug


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## dd68gto (Nov 14, 2012)

67goat said:


> dd68gto said:
> 
> 
> > You will find few here on this site or PZy that will want you to make that swap. It's very easy and will save you money in long run. Pontiac motor are becoming hard to find and you can get a crate 350 for 1/2 the price. I am a long time old Pontiac owner but I would rather see a Pontiac on road with a chevy motor than sitting in a back yard rusting away . Best luck and hope you change your mind but I do understand why you would do it Doug
> ...


Im sorry but you totally missed my point. Yes If you got a bottomless budget you can find and buy anything. Every engine you listed starts at 100000 and goes up to over 15000. If you can afford that then yes why swap to chevy . But for most kids they want the care on the road . Best luck Doug


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## bigD (Jul 21, 2016)

Maybe you guys missed my post.

I listed a real nice forged piston 400 long block for just under $5000. And a nice forged rod/piston 455 for under $6000.

Then I listed some cheaper cast piston engines for under $3000. 

Len Williams even shows an alum head 400 for $8g. And you can change or delete some of the parts & get it cheaper. So, you don't have to pay $10k & up for a decent Pontiac engine. 

400 Edelbrock Heads

But again, you're not gonna get a NEW Pontiac long block for $1800, like you can a 350 Chevy. Just a new aftermarket Pontiac block alone costs more than the new $1800 sbc longblock. Unless, your lucky, a good 400 or 455 block will cost $400-$600 or more. Then a decent set of screw-in stud head cores will cost $200 & up, plus shipping. Will cost around $600-$800 for a GOOD valve job, with new stainless valves, bronze guides, 7/16 studs, springs, positive valve stem seals, etc. Then you've got the rotating assembly, oil pump, cam, lifters, pushrods, rod main & cam bearings, gaskets all the machine work, etc, etc.

Some Pontiac engine builders have posted that they can't make a profit at Len Williams' prices. He supposedly has low overhead & does most of the work himself. Have never heard anything bad about his work. Some say he's a little slow. But, even at the high prices, some of the Big name Pontiac builders take longer. 

Butler sells ready to assemble short blocks for a reasonable price. But if you order this 1st one, I'd pay more & get some other block than a 500557. The most common good 400 block has a 481988 casting #.

https://butlerperformance.com/i-255...2-cu-in-unassembled.html?ref=category:1234783

https://butlerperformance.com/i-244...4-cu-in-unassembled.html?ref=category:1234783


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## dd68gto (Nov 14, 2012)

Have you bought any blocks recently and had a Pontiac built? When ? Long block is great but add at least 1500 to 2000 on top of that to finish. I do most of my own work. Pontiacs are my love. They are by far one of the most expensive motor to build. (American) Len Williams / Butler and s few other Pontiac only are good builders but ii think your way off on thinking you will get anything worth the time of day for less than 8000 from them and that's a starting price .i am talking complete carb to oil pan. You can find any thing you want on the internet but once you start hold on to your wallet those price they quote are get you in the door price and once you sign up your in for a long road.There are 100 of threads on this site and PY. I can't even think what a 3000 dollar crate 400 would be ??? All I was doing is stating the facts. If you got a Pontiac you can drop a chevy in it for 1/2 the money. Would I do it NO Can I understand why some would YES I'm done best luck Doug


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## dd68gto (Nov 14, 2012)

Just to understand I'm a Pontiac owner and would never drop s chevy in . But look at this 50000 mile or 30 month warranty. Also 3 years zero percent payment plan. I think we can all agree this is a 10000 plus motor with any Pontiac builder . https://www.summitracing.com/parts/...MIyc2iodHd4QIVSgOGCh1WjAbXEAQYBCABEgLLKvD_BwE
Doug


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## dd68gto (Nov 14, 2012)

Also free shipping and a 400 dollars future gift card on purchase . Doug


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## GTORAD (Jun 21, 2015)

I’m a Chevy guy and I would never consider swapping from Pontiac power in my 69 GTO convertible.


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## RogerL (Oct 15, 2021)

aem394 said:


> Hi, I am considering installing a small block chevy motor in my 66 LeMans. Has anyone done this? It’s a four speed car, any advice would be appreciated. Thanks


There are a lot of people here that are number matching hard core Pontiac fans and I totally get that. In my case however, I just wanted a powerful, reliable cruiser so I did swap the old 326 in my 66 Pontiac with a GM Performance ZZ6 405 hp 350. It was not a cost issue as many in this string imply. In fact, it is much more expensive than finding a Pontiac rebuilt engine. I made the swap out of a desire for reliable performance in a car I can drive daily. For this same reason, I also installed 4 wheel disc breaks, EFI, 200r4 transmission, Dakota Digital instrument cluster , new wire harness and QA-1 coil-over suspension. These things are not simple bolt in mods or cheap, but driving a reliable 66 convertible knowing I can ebb and flow in traffic without any issues makes it worth it to me. As others have mentioned, the actual cheapest approach is to simply find and buy a rebuilt Pontiac engine. Also, staying totally Pontiac will maintain the value of your OEM car. This should be carefully considered if you have a numbers matching GTO. If your car is an investment to you, don't deviate from the OEM design. In my case, I modified a 66 Tempest convertible which isn't worth nearly as much as a GTO. In your case, you have a 66 LeMans so your car is a good candidate for an engine swap too. Some specific advice: OPGI sells motor mount conversion plates that work perfect. The 200r4 trans is a very strong 4 speed with overdrive and you can use the same drive shaft if you want. Headman makes headers that fit perfect and buying a new wire harness will allow you to easily move the battery to the right side of the engine bay. The battery trays and fender wells in 1965,66 and 67s were actually designed to be mounted on either side of the engine bay, Take a look - you will see the mounting points.


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