ihave a 91 firebird with the 305 tbi i want to drop in a 350 but dont want to mess with all the computer and harness crap ive heard i can drop a 350 and use my same computer and harness. Can i do this? What about my heads can i use my 305 heads or should i use 350 heads? If i can do this do i have to get bigger injectorsor will my stock injectors work?

 

Im new to this too, but I think somone said in another thread that the 305 heads give you more compression than you would want for normal gasoline.
As for the fuel system i don't know, but you could use a carburator, ive got one and after adjusting the choke right it runs in the cold and starts just as good as an injected car

 

Here I figured it out

305 8.6
----- = ---
x 1


<------ that is my compression ratio, im assuming you
have the same.

305 x 1 / 8.6 = 35.47 <----- displacement of heads on 305

350 x
------ = ----
35.47 1

350 x 1 /35.47 = 9.87 <----- compression ratio of 350 with 305

heads

That is pretty high but i don't know if that is too much or not to run on 93 or whatever the highest octane your area has.

cant get this dumb thing to show the spaces and line up the numbers but you get the idea

 

i was told i should use 350 heads cause they have the bigger valves my stock intake should fit right in but i still dont know if my stock injectors will work, ive also got a chip in the ecm so i dont know how that'l affect it any help wold be appreciated