Well I was out at a wedding this past weekend when a friend of the famillies made me an offer I couldn't refuse. He has a 455 from a pontiac GTO that he was gonna use in his 1976 Malibu however he decided to drop that project and the engine wasn't gonna be used so he told me if I want it I can have it....so I took it. Its a big block 455 with a holley 750 double pumper carb. My plan is to get this thing to my mechanic and rebuild it. Also the Engine came with a TH400 Tranny which I also plan on getting rebuilt.

Here is the big question. My car currently has a 305. Obviously this 455 is gonna be bigger then the 305 and mostlikely a hell of alot heavier. What is it gonna take to drop the bad boy under the hood of my car. I am assuming suspension but exactly what do I need to buy. New struts? Springs? Strut Tower Bar?

Any advice would be great.

 

Checkout the pontiac V8 swap thread on the top of the page

 

I was talking to a someone the other day that knows a GM designer that's retired. He was saying that back when the 3rd gen came out, it had been in the design stages for about 6 years. The Firebirds were originally supposed to get the Pontiac motor. If you'll note at that time, Pontiac was still making a V8, that's why the car was designed with two battery trays in the front (the Pontiac motor has the starter on the driver side). He also pointed out that the Pontiac motor isn't too much heavier than a small block chevy. If you'll notice the PN's on springs for GPs are the same when equipped with a 305 Chevy, 307 Olds, or 301 Pontiac of those late 70s early 80s years. Pontiac Engines are pretty cool in 3rd gen Firebirds, and there are good parts out there from places like Butler Performance. There are even aftermarket blocks, heads, cranks, and rods out there for about the same price as BBC stuff. It just depends on how different you want to be.

 

im doing the swap right now(pontiac 400/th400). its not that hard of a swap. indian adventures makes the motor mounts, and spohn makes the trans crossmembers. its just a matter of how deep your pockets are.

as for the weight....i dont think its to the point that youd need different spring/struts/strut tower bar. i know im not doing any of those. i think the pontiac is just a hair heavier. but if you do any weight reduction, youll be fine. like i went manual steering, no cruise, no heat, no a/c, cut apart the wiring harness for the only things i needed, battery is in the hatch, no emmisions ****, and no front sway bar. i even went as far as taking out the whole interior just to get to all the insulation and tar paper(ironicly all of it together is pretty heavy).

if you use a aftermarket intake(i.e. single plane, or torker style) your stock hood will not work.

exhaust is the biggest problem im having now, ive tryed headers from gtos, firebird or many diff years, some big body cars, and nothing seems to even come close. and im really trying to stay away from the headers that indian adventures sells becuase theyre $600 in bare metal.

if you have any more questions, feel free...ive probably had the same question at one point.