Bought an 1983 Pontiac Firebird S/E and going to be fixing it up.



First thing was to pull the original 305 small block Chevy engine w/ trany.

Next is to buy a rebuilt Gen 2 461 Pontiac Engine


Going to need to do some conversions to get it to fit. Anyone have advise on a set of front springs to hold the new weight to keep the car straight?

 

That is going to be an interesting swap. Cant wait to see the progress

 

This is gonna be awesome!!! Subscribed.

 

It's not a "big block", except to the extent that Pontiac motors in general are somewhat bulkier than small block Chevy ones. All Pontiac blocks are the same "big"ness. Same bore spacing, all use the same cam, all the heads bolt up to all the blocks, etc., from the mid 60s on up to their demise. (they were the same size back before that but had other differences that precluded interchange) From the 301 to the 455. Only difference is that various displacements have one of 2 different deck heights, therefore require different width intakes.

The 455 such as you have there is one of the taller deck ones. Which will cause even more fitment problems than a short deck one would, but of course, gives you more cubes.

Let us know what you end up doing about the exhaust, transmission, and accessories.

Moog 5664 would probably be the best spring choice.

 

Thanks for the tip on the springs.

Some info on the engine:
Eagle crankshaft, the cast steel version
Eagle 462ci SIR 6.8" forged rods
Icon forged pistons
Hastings race rings
King bearings
Camshaft XR288HR (Pontiac)
Comp Endurex solid roller lifters
Scorpion roller Rockers 1.5:1
4X Cylinder heads
850 Holley Carb

It was recommended to me to get the Turbo400 transmission with torque converter and overdrive

 

What 4x heads did you go with? Did you have any work done to them?

 

I would do a 200r4 and throw some money at it during the rebuild. Bolt right up and can use factory 89 tta parts for the trans cross member.

 

Central Virginia Machine Service built the engine so I am not sure all what they did. Mentioned that the chamber is 96-100
Other number they gave me were

4.155 bore x 4.125 stroke
camshaft lift 0.236in x 0.242ex
.110 LSA

 

Quick question for you experts. Can you tell by these photos that the heads were baked in a thermal cleaner and blasted with stainless steel shot?

I was told by one person that they were, and told by another that they definitely were not. So, I have conflicting opinions. Thoughts?

 

More updates please.

 

 

Started the Engine on the Run stand. Ran into an issue.

After about 10 minutes, boiling water started up come up out of the top void on the center of the right head. My mechanic said the first time they ran it the top hose blew off. Really disappointing as I was hoping for a uneventful run. They think that a gasket may be blown. I contacted the builder about this and he thinks it may be a cracked head. Either way, it's going to have to be pulled apart to figure out what's going on.

 

That stinks....I'm excited to see this one take off.

 

Scorpion Rockers

 

Just got word that the heads where cracked. Going to send them back to the builder for a replacement pair.

 

Wow that sucks, how did you figure that out?

 

Cylinder head was Pressure tested at Machine shop. Shipped back to CVMS for a replacement

UPDATE: New head arrived Saturday. Now I can get the engine put back together

 

I had a local transmission shop build me a competition 4L60E transmission, with stall converter, computer (w/display & tuner) with the Holley RM-9070 bellhousing.

The heads are off the engine again and at the machine shop to fill in the EGR cavities.
The body/paint guy has been having personal problems that has kept my car on hold at his shop for the past 9 months. Not cool. The car is getting moved to another shop so it can get moving again.

Would anyone recommend a Procharger for this engine?

 

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