# Oil Pan and dipstick in engine swap?



## Lemanster70 (Jul 24, 2016)

Ok engine swap guys, i need to pick your brain:

oil pan: I have a 1970 LeMans Sport with the original 350 Pontiac TH350 combo and I am looking to swap in a 73-74 455 out of a Catalina 4 door. Can I use the oil pan off of the 455? will it fit the chassis of my A body?

Dipstick tube: The dipstick tube on the 455 was longer because the car had A/C, mine doesn't, the tube is 2 piece can I just take off the top piece and use the existing dipstick tube?

Engine mounts: from the research I have gathered from previous posts, I do not have to change frame or engine mounts correct? why did they have different ones for 455's then?

I really appreciate the feedback guys, this was an impromptu swap (see the article on Ram Air Restoration Exhaust)

Thanks!!


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## 1968gto421 (Mar 28, 2014)

I'm curious as to whether your stock A-body 70* oil filter housing on the 350 works with the Ram Air manifolds or is the 90* oil filter housing from the Catalina the one to use with the Ram Air manifolds? These manifolds seem to be more than a "bolt-on" part----now you have to do an engine swap to get them to fit (although a 455 can really rock and roll in an A-body!).

I'll be curious to see what you learn about the dipstick tube as my '68 has the A/C tube and it's a PITA to use.


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## Pinion head (Jan 3, 2015)

The factory oilpan on any factory '73 Pontiac V8 is dimensionally the same as the original oilpan on your '70 Pontiac 350. Only differences will be where the oil drain plug is ('70 was last year for front drain), & the '73 oilpan should have 3 small holes in the rear oil seal area to locate the first type of rubber seal that was used in '73, & I believe, '74 production. This first rubber type seal was replaced with the latter rubber seal that has multiple locating tabs & requires multiple slots in the oil pan seal area. With the '73 pan, its best to use the earlier cork style rear pan gasket, like was used on your '70 350. 

On the dipstick tubes, what your calling the lower tube is actually the intermediate tube, as the lower tube is actually a short tube is in the oil pan, & slides through the factory windage tray, or on your '73, this short curved lwr tube has a small steel bracket that bolts to a main cap. The visible intermediate tube is driven in from the crank side of the block, & yes, the short non AC '70 application oil dipstick can be used with the '73 tube combination. For those restorers missing their short non AC oil dipstick, just have to make sure if working on a '68 & later Pontiac V8's that don't use one from '67's and earlier... they are different.

If your '70 LeMans Pontiac V8 motor mounts are good, I'd first try & reuse them. Dont clean them in a solvent bath....have ran across guys doing that before, ruins them. There are problems with today's cheap '64-72 Pontiac V8 A-body motor mounts. They are not even of the quality of cheap local parts counter motor mounts from several decades ago. Installing today's cheap motor mounts, they can hold up, or the drivers side mount may destruct as the engine torques over. There are multiple discussions on this, you can buy the near $100 mity mounts, or modify your own parts counter motor mounts, what I've done to avoid this mess is buy old stock motor mounts, mainly out of old parts stocks. 

On the style of motor mount used on the '73 Pontiac big car 455, it is a long mount which bolts on with 3 short bolts, this motor mount was also used on:
- '70-73 Pontiac A-body's factory equipped with 455 engine
- '70-74 V8 Firebirds
- '71-74 Pontiac B series.
To run this style motor mount in a '68-72 A-body, will have to buy reproduction 70-72 455 A-body motor mount stands for $170, and source the correct long bolts. Most likely your going to be in for over $210, & then removing & replacing the original style motor mount stands, which for the average wrench, is a serious undertaking. Thus swapping to the '70-72 455 A-body stands, is not the wisest thing to do. Worse yet, parts store versions of thie long style motor mount have also been cheapened up. I have dozens of used examples of this latter style motor mount, & am seriously considering shipping several pair off to be revulcanized.

Hope this answers your questions.


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## PontiacJim (Dec 29, 2012)

Check your 455 as it should have 5 bosses drilled/tapped for the engine mounts. If it does, then simply position the Lemans engine mount to match on the 455, 350 to 455, and it will bolt in. If it only has the bosses, and they are not drilled & tapped, they can be. If no bosses, then you will have to use an aftermarket engine mount designed for the installation which will cost more as PH noted.


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## shader (Sep 7, 2016)

1968gto421

The ram air website seems to be somewhat “lite” when it comes to fitment info. When selling repop manifolds you would think the oil filter adaptor would be addressed, or maybe they figured the customer should have known or researched this. The factory used the angled adaptor on the early A-body ram airs to provide clearance. 

As for the missing exhaust bolt hole that’s not an issue unless you’re using tube headers. Starting in the 70s some head castings did not have the end holes drilled/tapped. One reason was probably a bean counter issue. Eliminating the drill/tap costs add up when producing a large volume of heads. Second, and maybe really the first reason, was that they weren’t needed. Cast iron manifolds are very ridged and apparently they sealed adequately without the end bolts. Also, in some cases the cast iron at the “bolt” end is very thin and there is not enough material to drill & tap.


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## Lemanster70 (Jul 24, 2016)

Thanks for the info guys, this is what I found out:

Oil pan is the same shape so it can be used. I can take off the upper portion of the dipstick tube and my A/C dipstick tube is now a non A/c one. non A/C dipstick will work just fine. 

oil filter housing is the same for ram air and non ram air for a '70. The one from the 350 and the 455 are identical.

Shader, you need these end bolt holes for these manifolds. If you don't have this bolt hole at the far end of cylinder 8, there will be nothing to seal the end port of the manifolds. There is no bolt hole in provision in the manifold between cylinders 6 and 8.

Thanks guys for all the input, I am anxious to get this thing freshened up and in the car!


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## shader (Sep 7, 2016)

Lemanster70,
Got it:surprise: Good to know about the manifold mounting. Fortunately mine are factory tapped. Again, ram air a bit lite on the fitment notes especially when due to the design the end bolt is needed.


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