I just recently purchased a few things to redo the top of my 305. I was wondering what my approximate horsepower would be after. Any help would the great, and please don't comment saying "do a whole rebuild with a 350" or something along those lines. It's a 87 trans am, 305 carbed, 081 heads, original exhaust however I will be gutting the cat converter, don't know what rear gears.

I purchased
Edelbrock 1406 600 cfm carb
1"spacer for carb
Edelbrock performer intake
Edelbrock performer plus camshaft
Hei distrubtor
New air cleaner and breather
Edelbrock 1.222 valve springs
Edelbrock shorty headers (don't know what kind)
Edelbrock dual roller timing chain
Accel shorty plugs and hi temp wires.

This is (my) first build but it's been a while since my dad has done one. The block hasnt ever been to a machine shop, and I'll also be running a stock compression. Any estimate would be a good estimate, thanks!

 

Maybe 30-60 hard to say depends how you tune the carb. Although it seems you may be doing more harm than good. The 87 block should be a roller block, going to a flat tappet is a step back. Same with the intake and carb. The performer is basically an aluminum factory intake and the edelbrock 1406 which is jetted for economy is not better than the stock CC Carb

 

I'd agree with Midias. You may get back to stock horsepower levels, but not much more than that. Stock carb and intake aren't your issue. Exhaust, then cam and tuning. New carb and intake would be last on my list and I wouldn't replace them with the choices you made.

 

Make sure your headers are thirdgen specific or they wont work. You best bet would be a decent set of 1 5/8 primary headers then 2.5" pipes off them to a 3" merger then a 3" exhaust. That is and should always be a starting point. After that look for a good roller camshaft if you have a roller block.

You probably have 2.73 gears so I would also pull the cover and check. Another great and possibly cheap mod would be a rear swap. Look on Craigslist, I just picked up a nice 3.73 eaton posi for a friend $300 2 years back. Took a little looking and a 1 hr drive but worth it.

Also just a side note I don't think your combo will fit under the stock hood.