Hi all;
I have a 92 firebird formula with about 207K on the o'l girl. Still runs great but starting to smoke a little and getting through smog is pretty close these days. So here in the next year I am planning on rebuilding the motor. There are several factors involved here. One I live in Califorina and two the stock 170 HP 305 CI TBI motor is just not enough power for this kid.

As there was only 1017 of these cars produced I am considering staying with the 305 block to keep the car numbers matching, however would like to modify the internals a little. Things such as a little higher compression and bump the cam up to perhaps a mid grade RV cam.

I also have a set of camel back 202 heads I was considering installing but not sure if they will fit on the 305 block as the cylinder diameter is not the same as a 350 CI motor.

The transmission has already been upgraded and rebuilt for more HP but not sure if the TBI system will handle the motor upgrades. Anyway, I am open to suggestions as this is not an emergency as the car is still running great but it won't be long I am sure till I have to do this. Thanks in advance for any comments or suggenstions.

Ron

 

Do you have to pass emissions?
How about visual check?

 

If you are worried about the numbers matching stuff why not find another block from a similar car and use it while saving the "born with" block? Because at the point that you're swapping heads/etc you run the risk of messing up the original block. If you got another 305 from 1992 (or 1991 depending on what month your car was built in) just a month or two older than the build date of your car it will be "numbers matching".

Then you can rebuild the born with motor to OE specs and have a nice trophy piece for 10 years down the road when you wanna do a full restore or something.

 

As CA has very tough emissions laws it would be a factor, however there is always the Magic $500 smog cert... (Taking the 5th amendment, LOL). Which I'd like to avoid... As to the visual if I do it correctly visually the only difference would be the two little humps on the front of the heads. I think / hope that would be overlooked as most smog shops don't know engine part that well.

 

RedLeader;
This also was a consideration in the process. Is getting a built 350 and using that and screw the smog but keep and rebuild the original and set it aside. As I am an old points and condenser guy I am not sure how much of a hassle it would be to lose the TBI. Not to mention I believe the transmission is electronic as well, correct?

 

double hump heads are pretty great, I'm always keeping an eye out at swap meets, etc

 

Yeah, I think in the later models the tranny and all that is electric. my 83 started out as tbi and we swapped it to a carb, but it also started as a roller (haha).

There are plenty of conversions and things to make stuff like that work, there are also aftermarket tbi's that do pretty well.

 

All depends on what you wanna spend, really.

 

There is a local shop here that will rebuild the bottom end to my specs. for around $900 bucks. I would be doing the head work myself. (porting and polishing) As I said, not sure if the 202's will even work on that block. I would think they would but as the cylinder diameter is a little smaller it is a concern. Also haven't really shopped around yet for an aftermarket TBI system but that is an option for sure.

 

For what it's worth (from digging into my 1st gen knowledge). If those are the DZ302 heads that I'm thinking of (two 'humps' on the front of the head) then I don't think they will fit based on info in this link:

https://www.thirdgen.org/forums/afte...ads-305-a.html