I have a 82 CFI camaro that I just got and am planning on swaping the engine to a 350 bored and stroked to 383. I know I will need new injectors, fuel pump, and PROM. Mt question is this, if I put a new cam in my 305 like a CS XE262H-10 will in be able to go on the 383? Would this be under camed. What if I went with the XE268H-10 grind, would the 305 still Idle. I am on a buget so anything I can keep from the old motor would be great. I believe the mainfold will swap over (would port it), is that a fact? Also I keep hereing about porting the throttle bodies. Is that porting the 305 TB's or the 350's. If I port the one on the 305 will that help my peformance and then go to the 383? Can I use the 305 heads on the 383 (I don't think I can but just asking for budget reasons.

And lastly can I run a power adder like NOS on a CFI set-up.

I would like to go CFI mostly to be different but I still want to be fast.

 

That's the problem with "different". It rarely equates to "fast".

CFI was one of GM's first attempts at power with economy and cleaner exhaust. While it accomplished the task in factory form, it was largely a failed effort in the larger performance community. There is nothing fundamentally "wrong" with crossfiring two throttle bodies, but GM never took it as far as possible, and the aftermarket never picked up on it.

I don't know off-hand if the 305 and 350 manifolds were different. I do know at least one aftermarket manifold was offered, it was expensive (something like $450), and didn't really flow that well compared to a simple dual-plane carb manifold. One racer I know with a 350 CFI Vette gave up on the thing after spending a bunch of money just to get into the 14's (at altitude - 13's at sea level). When it qualified for collector plates, which don't require emissions testing, he converted it to carb and was instantly in the low 13's - at altitude. And that was with a 350.

The cam you listed would be fine. The XE268 would probably require PROM tuning. Either would swap over to the 383, but you can be sure PROM tuning is in your future. I'm way over my head whether that can be done easily on a CFI ECM.

Porting the stock manifold isn't going to get you much. The ugly truth is CFI will be a severe restriction on a 383, so you're going to have to decide how slow a "different" set-up you can live with.