im new to the third gen world but i just got a 91 firebird formula with a 305 tbi motor in it and i bought a whipple twin screw supercharger to mount on it i have a few questions about this however my motor is basically stock it only has 1300 miles on it and besides a high perf oil pump and 8.5 to 1 compression she is all oem new stuff but oem. how much boost can a safely run and whats a good head and cam selection for my set up

 

I wouldn't typically run more than 7 or 8 PSI with stock internals. As for cams and head selection, I'll say what everyone else is going to tell you: Don't waste money on a 305. You'll get more for your money with a 350. If you are hell bent on using the 305 then you'll really need to either have the stock heads ported or you'll need to find 305 specific heads. I think AFR made some a few years back and there are some still out there you might be able to pick up. Again I wouldn't really waste the money on building up a 305. 350 blocks are cheap and plentiful.

 

im not hell bent on the 305 i know its not exactly the best motor option but the motor is brand new so im not going to swap it out for a while what size should i port it to? and what about the cam

 

also how much spray can she hold because i have a kit that has a 50 shot nozzle

 

I'm talking about porting the heads so they'll flow better. You may need to replace the heads, as I understand it the 305TBI heads are terrible as is the cam. You could stroke the engine to a 335 but that would require pulling it and having it machined. Not worth the money given that you could probably do a 350 for the same price including the block. You need a cam that would be boost friendly and computer friendly. I'm not sure about TBI setups as I've never had one in a third gen and don't really like it in general. I'd call Comp Cams and talk to them. They are pretty good about dialing in what it is you are looking for. They'll tell you which of their cams is best or they can create a custom cam for you.

If you are going to supercharge the engine I fail to see the point. Yes there are people that do both, but if your already running 7 to 8 PSI on the stock internals of the 305, you'll pretty much be at the "safe" limits of a stock engine. Throwing nitrous into it at that point is asking for trouble.