So I have a BW 9 bolt in my car now. It does have 3.27 gears in it and I was thinking of going to 3.70's or 4.10's. Don't know if 4.10's is just going too far and I am looking for opinions from my third gen group. So, here is some back ground. I have a 85 TA that came with the 305 TPI and a 700R4 behind it. I have changed the auto to a T5 5speed from a z car I had sitting around. I have been running the 305, but it leaked oil like a sprug well. the car sat for 7 years before I started it up, so all the seals were dead and shot. the clutch slips a bit on take off and don't know if the gears were just too high? or if the oil leakage was pissing off the clutch. I have taken out the 305 this weekend and have a 350 that I rebuild to go back in. so..... whew after reading all of that what is your 2 cents? OH, BTW I will be mostly street driving this car around town. probably hardly to none freeway driving. this is just my fun car I drive once in a while. and I do like to take off hard at the lights once in a while. Hope this is enough info for some opinions.

thanks all!!!!!!!!!!!!

Ken

p.s. HAPPY NEW YEAR TO ALL

 

3.70 sounds like the best bet.

Assuming of course, that it's not TPI; if it is, 3.45 is about as far as you want to go, due to TPI's RPM-preventing effects.

 

I did not know that, yes it is tuned port injection. thanks so much!

 

Right:

That intake system is designed to produce a "Mount Everest" of power at 3600 RPM, at the expense of ANY power above that. Very good for stoplight-to-stoplight seat-of-the-pants "feel"; but not much else.

If you've ever driven a tractor, you'll have a better feel for what will happen with too much gear behind a TPI motor. You get this tremendous rush of power at low speeds when you stomp on it, if it's like my tractor it'll pull the front wheels; but it'll only go ... snail speed. The engine just simply won't go any faster. That's what too much gear is like. You'll be able to SMOKE the tires at a stop, but won't be able to pass a semi at 55mph on a 2-lane road. 0-60 in 5 seconds, 60-70 takes a minute, won't go faster than 70 even if you hold it floored til it runs out of gas. That kind of thing.

 

OK, that makes sense, I am so glad I asked. I probably would have gone the wrong way. I think I will examine the clutch when I take it off the old motor and see if it may be oily. maybe that is why is was slipping a bit. just felt like it had too much power and the clutch couldn't hold it. We all know that with a 305 that couldn't be the case. Only other thing I could think of was the 3.27's were too high.