Is my 89 TBI 305 a roller motor or not??? Also, what type of heads are on my car???? Know these sound stupid, but I have read conflicting things on the year models....All stock motor, thanks, Tom

 

If you are sure that your motor is all stock (not replaced, modified, etc from a previous owner) than your motor is a roller motor with a one piece rear main seal. Your heads are swirl port heads with the last three digits of the casting number being 187 (pull a valve cover and you can check to be 100% sure, takes about 5 minutes). They have an advertised 58cc combustion chamber (although Fast55, IIRC, has CC'd them from 56 to 60 CC's. In stock untouched for them should flow around 165cfm on the intake side and support near 290hp. Being swirl port heads, (really a fast burn head) they do not necessitate a lot of initial timing (best at 0° to 4° advanced on a stock set-up). The f-body TBI motors didn't change throughout the years from '89 to '92. This is just a quick cliff notes version that should get you started.

 

Shifty, Thank you very much for the info...Very usefull...I thought thats how it was, but then I read something else...I am 100% sure it is stock.......Thanks again, Tom