Here is my scenario. I have a 305 tbi 89 trans am. I currently have headers, y pipe, 3 inch flowmaster catback, 3.73 gears with stock automatic transmission, open element, k&n filter, turbocity spacer, free tbi mods, edelbrock tbi performer intake manifold, 160* stat, and power pulleys. My car is still slow. I was wondering what junkyard heads (better than stock) are compatible with the lo3 (cost) and some aftermarket heads. I believe that i will need to upgrade the fuel so am i stuck since i have the performer manifold. Whats my options with current manifold and is there a better alternative that i should upgrade to. What should i do about the tbi also (bigger or stay and just do injectors)??????? Thanks for the help and sorry for the long post.

 

Hey welcome to the boards. Since you already have the "foundation" mods you are off to a good start. The next thing that you need to do is get rid of the stock heads and cam. That is why your car is so slow. However this needs to be planned out and you need a few very important upgrades before you start wrenchin' away.

You need an upgraded fuel system witha high flow fuel pump.
With heads and cam set-up you will need larger injectors and a larger than stock TBI unit. You can get away with a stock unit with 350 injectors but you will not be getting the most out of your combo. Most importantly is chip burning. You will go nowhere unless you have a custom chip and tune your set-up. If you have lots of money it is easy to do all of this at once. however if you are like most other thirdgenners you are broke and have to do mods in long drawn out self savings plans. So If I were you I would upgrade your fuel pump, do the ultimate TBI mods to your TBI unit and reseach a heads and cam set-up and custom chip burning. Than I would purchase the larger injectors, heads and cam and everything you need and set them aside. After you learn, or have done via friend, your own chip burning you can put everything together and tune it the day it gets all put on. There are a lot of week links on these cars and you kinda have to do a lot of things at once when to get to the modding that you want to do.

As for heads. The 416 heads (LB9 cars right guys?) came off the 305 TPI and are nice cheap heads you can get from a yard. You can port these nicely and have some really nice gains when matched to a cam. There are plenty other heads out there but it depends on what kinda of power you want to make, and if you are keeping emmisions. Any cheavy heads will fit your 305 but that doesn't mean you can use them all. That depends on your set up and goals. You may have to mill some to achieve a small chamber size, you may have to do srping work to accpet a larger cam. The list goes on. I hope I helped.

 

416s came on l69s, lg4s, and 85-86 maybe 87 lb9s so ive been told.

 

416's did not come on 87 TPI, they got centerbolt style heads.

 

i couldnt remember if you included 87 or not, thats why i said maybe. youre the one i got the info from.