i have a 91 firebird formula 305 tpi 5speed and was just curious as to what your opinions are on that motor. i believe it is the 230 horse motor as it has dual cats and does seem to have alot of power for a 305. Its got about 150k on it but until recently (small computer problem) it seems to run like brand new

do you think its worth keeping it and dumping say 1000 into it? or would u say just save up for a 350? i was thinking somthing like headers, a chip then vortec heads, a cam and some kind of intake? im not realy fond of nitrous especialy on a 150k motor but how far would those mods take me? i do like the motor and love the 5 spd but realy have never driven a thrid gen with a 350

i do drive the car everyday and gas does matter a little i mean i dont drive very far but filling it up to often would get annoying i just would like a reliable performer that i can take to the track and put down numbers that my freinds in there damn vws and stuff cant touch im just reachen for maybe mid-low 13s but again i dont realy go tot the track to much thanks alot for any help

 

Run it till it breaks.

Upgrades like vortec heads and intake or a cam if thats what your wanting to do can easily be transferred to a 350 or even another 305 if u build/rebuild another motor down the line. So will headers/catback/etc.

Just keep in mind your delaing with a 150k motor you want to romp on and do your mods accordingly. Stick to things u know you will use on another engine and have fun wringing out the 305 until u kill it.

later
Jeremy

 

What he said!

I have lost barely any fuel mileage with my combo..

 

305 and 350s have the same exhaust ports so you can get headers now and transfer them over to the new engine. I'm in the same position but I have the 305 with a peanut cam. I'm thinking 350 block, ported plenum, Vortec heads, roller cam for a daily driven setup.

 

Not sure what your performance goals are but 305s can run good. Many of us are in the 13s without too much work. Just make sure your bottom end is tight before you go slappin heads and cam on an old motor like that. Its not too expensive to re-ring and install new bearings ya know. at least then you would have a tight bottom end to start with.

 

I just ran a best of 15.4 @ 87 w/2.1 60's last week during my first time to the track. I have a LB9 car with auto. I have put full exhaust, gears, and K&Ns. Not fast, but 142K miles prolly did the poor thing in...time for a new engine.

 

My 305 is quite a bit fresher w/ only 56k on it but my 85' Lb9 w/ a World Class T5 (center force clutch) and no other mods but headers a cut out some 1.6 rockers and a ported TPI w/ SLP runners ran a 14.6 at 96.3 mph. Given that my best 60' was a dismal 2.23, i think 13s are doable w/ some suspension stuff, some computer tunning and some practice. Add heads and a bigger cam and I dont think 12s are entirely out of the question. Run that 305 into the ground, then get a 350. Thats what I plan to do. I may take a Loooooong while i my case tho.

 

That's like everything but a cam and heads.... Sorry, just giving you a hard time. No harm no foul.

As for me, I like having a 305 and it holds it's own against "newer faster cars" especially since my car is stock. I plan on modding this thing until it blows then getting a nice 350 and transferring everything over at that time, but that doesn't mean I want the 305 to go.