[Ryche400]

I recently scored a complete running 455/TH400 drivetrain. I currently have a 400 in my car. Can I use my headers, intake, valve covers, and rockers on my 455? I just plan to install a new cam, lifters, timing chain, oil pump, and re-seal the engine. It was out of a perfectly running car.

[BILTIT]

Yes to all. Headers may be the exception, depends if heads are round port or d-port configuration, 90% sure they will work. Motor mounts are the other exception, not all blocks have all the same mounting holes (some have only 3 holes, others have all 5.)

[hisgto]

What Biltit said.

Did you score the engine for free?

[Will]

All internal and external parts interchange beetween all Pontiac V8s (except 301 and 265) except the following: Blocks, pistons, cranks. Cranks interchange between 400 and smaller engines, and 421 and larger engines though the strokes may be different. Heads swap between all Pontiac V8s, as do rods, rockers, pushrods, valves (some length changes over the years), distributors, all external sheetmetal and timing covers, water pumps, manifolds, etc. etc.

[Thumpin455_GTO]

in addition to what the others said...intake manifold change in 65, previous intakes wont fit later heads without rework. Valve inclination angle change in 67, could hit pistons with later heads on earlier engines. Two different water pumps, and some mount changes. Pre 70 blocks need adapters to fit in a 77-81 bird. But that doesnt matter here.

As for a 455 in a 2nd gen bird, it will fit right in there using all the stuff the 400 had, assuming they are D ports and it doesnt have the early water pump. Swapping a cam and lifters is a good idea as long as you dont go too big.

What heads does the 455 and 400 have? You might be able to use the 400 heads for more power. 114cc chambers arent so great for NA combinations.

[quicksilver97ta]

On the heads, be sure to check if all the bolt holes for the exhaust manifolds/headers are drilled and tapped, sometimes they are not.

[Thumpin455_GTO]

Originally Posted by quicksilver97ta

On the heads, be sure to check if all the bolt holes for the exhaust manifolds/headers are drilled and tapped, sometimes they are not.

Yep, heads in 1972 were that way. Some didnt even have the metal there to put a hole in.

[Ryche400]

They are both 4X heads. So im sure the headers will work. I was able to buy the drive train for a cool 300 bucks. A guy needed some body and suspension parts for his 72 Catalina. We both bought a complete running car. I got everything attatched to the engine. Even the a/c compressor was still working. I got lucky cause the car had a new alternator, starter, and fuel pump. Even the factory Q-jet had a fresh rebuild.

[form406]

they may be dfferent size 4X heads...use the 400 4X's after you check cc sizes...they are most like like smaller cc heads which is better for 455...