th350 or 700r4?
For race app. I would go with the th350. With that 4.10 and the 700's low first gear, as soon as you hit it you'll have to shift and that gap on ther 1-2 shift is hell. Not the best for ET's. Loved my th350, the way it behaved and no TV cable to deal with. The ONLY reason I went to the 700 was to have the OD. The low 1st gear was non-issue on the decision to swap.
Thread Starter
Staging Lane
Joined: Jan 2008
Posts: 50
Likes: 0
From: canada
I wonder if a 4.30 and the TH350 would work, or if the 1-2 would be too short again. I found this calculator (nationaldrivetrain web site) according to it, if I go through the traps at 107.37mph I should be reving 5000rpm with 3.73 gears and a 27" tire(I think this is about right, but who lets off at the exact time they cross, so it's hard too tell), going to 4.30's would only jump it to 5750rpm, my car peaked at 5540rpm on the dyno, a couple hundred rpm over shouldn't hurt, when I build my 383 I'll cam it to suit.
I don't know
hmmm
I don't know
hmmm
Gear ratio in the rear has no factor on gearing internally on the trans. The th350 is 2.52-1st, 1.52-2nd, 1.00-3rd. The 700 is 3.08-1st, 1.62-2nd, 1.00-3rd. Look at the ratio difference, from 1st to 2nd on both trannys. The RPM drop is a power killer between the 1-2 shift on the 700. Therefore, ET will suffer some what. Deal breaker? No, look at the 4l60's in the 4th gens. They run pretty well BUT, look at the ones with the 4l80 trans, hmmm. The gearing is a lot better between shifts and those guys seem to ET better. Back on topic, TH350 is the one I would go with for race/best ET.
