Search for a guy named Willie (screenname too) both here and over at TGO. He's got a very nice, very clean supercharged 305 car that runs well. May also want to lookup BADDEST305. He had a low 12 second 305 NA that ran deep 11s I believe when spraying.

 

Thanks a bunch i will look it up right away. I was also on TGO just last night looking this up too. thanks though.

 

http://www.thirdgen.org/techboard/tp...tpi-310-a.html

 

Its the exhaust. The 305 5-speeds with the dual-cats have the same exhaust as the 350's with dual cats. Larger 2 1/8" outlets, dual 2 1/4" y-pipe to dual 2 1/4" cats, and a 2.75" cat-back.

The single cat 305's, with automatics and T5's, have the same exhaust as the 305 TBI cars. Smaller 2" outlets, a single 2 1/4" y-pipe with a single 2 1/4" cat, and a 2 1/4" cat-back. Changing the exhaust on these cars will give you the 25 horsepower back.

And if you doubt how much power a good exhaust setup is worth, my father had a guy with a 350 carb'd engine in a Chevy truck come to him back in the early 90's. It had the whole Edelbrock power package on it, including cam, heads, and headers. It dynoed a whopping 160 HP to the wheels. My dad noticed the y-pipe on the Edelbrock headers was more like a T-pipe, with one pipe going into the side of the other. My dad cut that off and remade the connection into a true Y. The owner had it redynoed and it now made 210 HP to the wheels. That's a 50 horsepower gain just from a y-pipe change.

 

What really holds back a 305 is the 3500lb car it has to move