Andrew6.688

Hello ThirdGen! I've lurked for a while, loved third gens since my parents brought me home from the hospital in my dads 89, back in 93. Grew up helping him clean it and have very fond memories of what was really a dog v6 auto car (had a dealership applied GTA body kit, was called GTX if i recall...)

I've had a 4th gen for just about 3 years and it was my first real dive into automotive maintenance and repair .

This past spring a friend sold me a 97k mile 1991 WS6 305 5 speed car, running on 7 cylinders for a whopping 900 bucks thanks to a destroyed valve spring.

I took her apart and replaced the head gaskets, valve sprigs, seals, and lapped the valves with a light compound. Edlebrock tpi intake and runners. comp cams 1.5 rocker arms. Found out that the 305 has a mild cam in it, but not sure the specs. sounds good, but its not hard to drive. I can get it to idle about 850, any lower and its hard to drive.

Also found that it has late tpi aluminum corvette heads, casting 10088113 ( i think). Theres a flowmaster muffler, i had a high flow cat put on and the exhaust tucked up so i could lower the car, and the piping is all about 3" or 2.75"

It sounds awesome, i have the ignition turned to about 14 btdc at idle, running high octane, but the car is a total dog. theres no torque to speak of, falls on its face below 3700 or so, especially if your in higher gears and you dont downshift. I knew the 305 was a dog, but this thing is makes a little bit of power between 4000-5500, and feels like it wants to go higher, but without knowing the history of the car (and finding a broken valve spring) I am scared to rev it over 5500
Hopefully someone with some 305 skills can help sort it out, i've been told by other 305 owners that it should haul up to about 4k then choke, and mine seems to do the opposite!

Thanks!

Night rider327

iTrader: (13)

Good to see another Georgia member.
That's an odd prob you have. You are correct the 305 and the TPI system both does much better with low to mid range torque.

It's not a stock engine, it has been played with, so my only guess would be a bigger cam than you think is in it and that for sure would kill off low speed torque. Also with bigger cams, and better intake and all, the stock tune on computer hurts you.

My 1st thought put a compression gauge on it and see what your cylinder pressure is. This can give you an idea of the cam size as bigger cams will 'bleed off' cylinder pressure.

Andrew6.688

Hopefully sometime i can drive a 305 5 speed in closer to stock trim and see what mines doing wrong.

Depending if i sell the car (kinda looking for a cheap daily) i might just throw a caprice/roadmaster lt1 in the thing and try not to blow the t5 wc

Night rider327

iTrader: (13)

Yeah the T5s can be tricky. If you don't have sticky tires, don't do high rpm clutch dumps and don't speed shift the thing they will last for a while.

What part of Atlanta are you in? Im in Bowdon, GA just south of carrollton, about 55 miles west of Atlanta.

If you wanted to do an engine swap. I have something you might be interested in. I have a '97 vortec 350 roller cam short block for $350 (I would let a TGO member and fellow third gen'er have it for $300).

Andrew6.688

wow wish i had the cash for that, i assume that its a bolt in swap and tune for the added 45 cubes? Right now i'm living in Woodstock, about 35 miles north of atlanta, with my parents for the week. thought i was going to be spending the next 3 years in Auburn for school, didnt work out.

Next week i'm moving to acworth, about 25 min south of cartersville.

I'm currently a broke and in college, but if i get the money (and still have the car) any time soon i will jump on that

Night rider327

iTrader: (13)

Oh cool, small world man. I know both of those places VERY well. My Uncle use to live in woodstock near sixes creek and my buddy's dad had a transmission shop on dupree road right before the 575 bridge in woodstock.

I grew up in Dallas, GA.. (about 2 miles from the dragstrip...that's no longer there) and was around acworth ALOT. Went camping at red top mt. state park more times than I can count. Fished at allatoona lake all the time. I got into "sales" by selling at the highway 41 flea market and great american flea market with my dad up there on highway 41 when I was a kid and young teen (they are no longer there, I think a wal mart super store is where the 41 flea market use to be)

Went to the the days auto auction many times up there on 41.

Sorry for the rambling on, just a little trip down memory lane for me.

Yeah the vortec 350 short block would be a bolt in swap, if you used your heads, intake, etc it would go in just like yours now. If you used vortec heads on it, you would need a diff intake.

91RS5speed

Stock timing is 6 degrees advanced. I would start at that and work my way up to see how it runs.

Andrew6.688

yeah i've bumped my initial timing up to about 15 so maybe its the problem. Anyone have a problem with the starter? Mine sometimes hesitates to start, turn the key nothing, maybe 3 seconds later the motor starts turning over. sometimes i just take the key out, try again. doesnt seem to be a problem if the cars been warmed up.