# '76 400 into '66 Lemans, motor mount issues



## JB_Finesse (Jul 15, 2009)

The motor mounts off my 326 don't fit it. What kind do I need? I'm trying to have the 400 in the car and running this weekend.


----------



## pontiac (Mar 6, 2011)

actually they should, look at your block, are the two furthermost front machine pads both drilled and tapped. Each side should have 3 machine pads for the two kinds of mounts, early and late model. it is possible you got one of those blocks which did not get tapped and drilled. So you either need to do that and buy the adapters to allow the later block to mount into the older car.


----------



## likethat (Oct 5, 2007)

Ron's Pontiac Page: Engine Block ID HOWTO


----------



## JB_Finesse (Jul 15, 2009)

Block's cracked. Looks like I'm going with a 454 now.


----------



## Too Many Projects (Nov 15, 2008)

JB_Finesse said:


> Block's cracked. Looks like I'm going with a 454 now.


454, as in Chevy ???? Have fun with that change-over. Hope you have a Chev transmission too and can run the fuel line to the opposite side of the engine bay along with the starter wires, different exhaust, etc. etc....
Be a WHOLE lot easier to just find a good Pontiac engine.


----------



## JB_Finesse (Jul 15, 2009)

My mechanic swears he can do everything required and he has a line on a good, cheap, 454 that is a guaranteed runner. I need a new exhaust anyway and a common Chevy pattern TH400 will be a step up from my current ST300 2-speed. If I could find a good, running Pontiac engine that wasn't a $2500+ crate engine I wouldn't have been desperate enough to buy that piece of **** '76 400 in the first place.


----------



## Instg8ter (Sep 28, 2010)

hold out for a Pontiac block, don't desecrate your Poncho with a chevy motor...plus you will be in the same boat as the Chevelles getting your A** kicked on the street by torque rich 400-455's. Poncho blocks are out there at reasonable prices you just need to look, just sold a 71' 455+.o60 short block for 400.00 in need of two sleeves (150 ea.) add a set of 6x - 4 heads and a good cam and your at 430hp/520tq with stock parts and all in at 5,500 RPM. And when someone "swears" they can do everything required, you better get out your check book, since nothing would be required but mounts to put in ANY pontiac block from 66-76. Save the fab money and put it towards your Pontiac motor.


----------



## JB_Finesse (Jul 15, 2009)

Hey, at least I'm not being a total cheese**** and putting a SBC in my car. Maybe I'm crazy but driving a 454-powered Cheviac LeMalibu sounds like a better Summer than leaving my LeMans a lawn ornament for however long it'll take to find a good 455 and build it into something like Instag8ter's setup. Later on I'll build a 455 and drop it in along with a Muncie M21.


----------



## Too Many Projects (Nov 15, 2008)

If you can buy a crate Pontiac engine for $2500, that would really be the way to go. Get your mechanic to put on paper everything needed for a swap to Chevy powertrain with cost and install labor. I'm betting it won't be much less than a Pontiac engine or possibly more. Newer 454's don't have a provision for mechanical fuel pump, so an electric pump and wiring is an added cost. Also nearly all of them came out of a truck and the oil pan won't fit an A body frame. My recently purchased 66 Chevelle (same frame) came with a '93 454 truck engine and the PO bashed in the firewall and relocated everything back 2 inches to avoid spending $200 on a gen V conversion pan. All this adds up quick and makes for a LOT of extra work that will raise the labor bill far beyond a simple engine swap. 

I urge you to get the cost on paper to make a realistic evaluation of the swap. Your mechanic may well be capable of this and anything can be done with enough time and fabrication. The bottom line here is..........is it really any cheaper than to get a correct engine....:confused


----------



## Instg8ter (Sep 28, 2010)

Cheviac LeMalibu 

LMAO, that sounds like a rare neurological disorder ....Don't take my comments wrong JB, just sounds like a lot of work to get up and running and if you ever do decide to go back to a poncho block you will have to undo it. What about selling the 454 to finance a built 400-455, Like TMP said, crate motor and a weekend and your up and running. I built my Motor myself, will be going in this weekend (hopefully vid to follow). Got long block from a trailer queen that was put back to original 389, had less than 2000 miles for 300.00 w/forged TRW's, 6x-4 heads from the previously mentioned (sold) block with Harland Sharp roller rockers and comp cam springs, guide plates and push rods....all said have maybe 2,500-3000 in motor 700 of which was machining...deals are out there you just have to be patient and pull the trigger when you find them. E-bay and Craigs List are 24-7 swapmeets....moto on this build was "if it's not 1/2 off retail i don't need it".


----------

