BIG BLOCK SWAP ON AN 86 GP

[TURNA]

Before you do anything.

Double check that the engine is actually a pass. car 454 and not a 366, 427, or 454 tall deck.

After that, if it is a pass. car 454 the swap is easy.

If it is a tall deck I would pass on it.

There great for a track engine but on the street and highway you will not be happy at all.

The 454 goes in the same location as the SBC with the same mounts.

The driveshaft length has nothing to do with the engine placement.

if you are using the trans that is already in the car. The trans will be in the same exact location.

If the motorhome has a t400 in it or a 700r4 trans (they were avalible in 83) you will need to modify the crossmember and driveshaft.

There is also a truck t400 and a pass. car t400. Truck has a bolt on yoke the car a slip on.


If your handy you can get the Hooker 2455's to fit with very minor mods and save yourself a bunch of $$$

 

[TURNA]

Oh and if it is a tall deck

You can not use parts off of it for pass big block

the heads are the worst

the rods and pistons are different

the distributer is different

intake is different


The cranks are steel but they are weighted differently for the different rods/pistons

 

[GRANDPRIX350]

OK THANKS BUT HOW CAN I TELL THE DIFFERENCE? iT CAME OUT OF A P30 CHASSIS MOTORHOME?

 

[TURNA]

OK THANKS BUT HOW CAN I TELL THE DIFFERENCE? iT CAME OUT OF A P30 CHASSIS MOTORHOME?

block casting number, head casting number

 

[Kiko]

I'm pretty sure all your questions were answered. However, if you need anything else, please let me know since I've done exactly that -- a 454 crate in an 83 GP, with headers, etc. I've swapped a 700R4 but never had to cut the drive shaft. The original engine when I bought the car was a 305 V8 with a 7.5 rear end.

Good luck with the project and keep us posted.

Andry

 

[TURNA]

I'm pretty sure all your questions were answered. However, if you need anything else, please let me know since I've done exactly that -- a 454 crate in an 83 GP, with headers, etc. I've swapped a 700R4 but never had to cut the drive shaft. The original engine when I bought the car was a 305 V8 with a 7.5 rear end.

Good luck with the project and keep us posted.

Andry

You have a 700r4 in your Grand Prix now? What trans did it originaly have that you did not have to cut the driveshaft?

 

[gk666]

YES MORE BB G BODIES

 

[Kiko]

Turna,

I factory ordered my 83 GP in Aug 1982 and it came with a TH250 (2.73 ratio) and a SBC 305 V8. I bought the car knowing that I'd be replacing the engine with a 350 that I was working on, and at the same time I put a TH350 (3.23 ratio) with Positraction and shift kit. About 6 years later, a tappet spring failed and a valve went thru the block, so I put another 350 in it and changed to a 700R4. Great combo! The drive shaft was never changed.

The last go-around (present configuration) is a crate 454 with lots of other goodies, but the 700R4 and original drive shaft remain. I'll be changing the rear end on the car in the near future because the original 7.5 won't take the torque of the new BB 454.

Hope this helps.
Andry

 

[anakputa]

Never cut the driveshaft? I had to cut mine when I did the 3.8 to 355 SBC 700R4 swap..

 

[nycutlass]

what mods would u need to do to them ?

If your handy you can get the Hooker 2455's to fit with very minor mods and save yourself a bunch of $$$