OK , i got a '89 Firebird with an LO3 . Since 2 years iv'been running it with a huge exhaust leak (I mean huge : manifold , muffler , just after the y pipe ...) . Now i just bought hedman hedders 1 5/8 shortys and 2 1/2 y pipe and ordered a 3'' cat-back from Flowmaster . The engine has an open air element , but it is otherwise completely stock and runs really nice for a 343k motor . Right now it made 16.6 passes (lame) . Is it a good combo for a TBI car ? Will it beneficiate from an intake ? What kind of time slips should I expect ?

 

340,000 miles !!!!!

I'd be happy that it would even drive a quarter mile let alone do it in less than 17 seconds.

A fresh 305 with those mods and your 2.73 gears should run high 15's, a gear swap would get you into the low 15's.

Your next step would be a cam swap and diy tuning. This could get you into the mid to low 14's with it tuned properly.

Seriously, a rebuild or 350 swap would be next on my list of things to do.

 

Actually , its 344 000 kilometers ...

 

I had a sbc 400 .030 oversized , decked . But I sold it ...