Hey everyone, I have a few questions on heads for the 305. I have an 92 RS (L03 TBI). The only mods so far are a compu-cam, edelbrock headers, K&N filter, and hooker catback.
Now, please correct me if i'm wrong on the following, I do not know much about heads:
The L03's heads suck, their intake valuves are smaller than 1.94".
They have 54cc combustion chambers?
350 heads flow better, and have 1.94" intake valves (except for the double humps that 2.02"). However, they have 64cc combustion chambers?
So, my main question is would standard 350 heads help my 305 since they have better airflow (but less compression)???
If not, what are good heads for the 305 that I can get cheap (casting numbers would be nice )? (me poor). I don't want to spend much on this motor, but I want to do something to hold me over since my dream motor is at least 2 years off (must graduate college).
Thanks alot!

 

The LO3 heads are known as "swirl port". Nice low-end grunt, terrible for performance. Intake valve size is 1.84". Chamber size is 58cc.

There are a lot of different 350 heads out there. Truck heads with 1.72" intake valves, 76cc chambers. Those would hurt you. L98 350 heads, like those put in 3rd gens, have 1.94" intake valves, 64cc chambers. The compression loss would be significant, extra flow would probably not make up for it.

The best 305 factory heads would probably be LB9 TPI heads. Don't know the casting number (have one sitting at home). Still 1.84" intake valve, 58cc chamber, but the intake port is more open. Putting in 1.94" valves & better springs, a little porting work to open up/smooth flow, would be a nice improvement.

 

The alum. vette heads 87 up to ? have 1.94/1.50 and 58cc chambers and will work with pre 87 intkae manifolds. If youcould get a used set cheap[in good shape] they would increase hp and or half the weight.