Anyone swapped to an OD automatic and received improved E.T.'s or mileage? Can you give details?

I know there are at least a couple people who post here that have good E.T. and/or mileage results with OD trannies. I'm considering looking for a tranny at the Spring swap meets to build up so I thought I'd ask to get an idea of the improvements you folks have seen.

Thanks!

I can tell you what my RPMS went to smile.gif its a new motor with a 700-r4 and at 1:1 ( drive) it goes at about 3000 on the highway .. put it in Overdrive and it goes down to near 2000.. I put about 1200 CAD inparts into the tranny and it is very solid. Its running behind a 400+hp motor! Shifts damn hard!

A lot of info here (http://www.drivetrain.com/new_overdrive/GM4speedautomatic/overdrivegm4spdauto.html)

The lower 3.06 1st gear ratio can be a great advantage if you can get it to hook. I think most performance gains are about .20 in the 1/4.
200R4's and 4L80E's have a lesser spread between 1st and 2nd gear ratios which is theoretically better for drag racing. But that 3.06 fisrt gear in a 700 can get a big heavy car to move easier.

Thanks.

Anyone else?

I just had the TH-350 swapped out with a 700R4 about 2 weeks ago. I went from maybe 12mpg to almost 15mpg. Might have been better if I can keep my foot out of the gas. I can tell a you there is a difference, not a hugh one but more than a little. And on the road at 70 the engine is purring, can't tell you the RPM's cause I don't have a tach(yet). IMO it is worth it to do the swap. :D

Thanks koolbreeze. What's your rear gear? Small or big block?

I put a 700r4 behind my 402bb with a th400 it went from about 3400rpm @75mph to about 2300rpm/3.42 rear gear... :D

Then I put a 200r4 behind my 350HO with a th350 and with the same results/with a 3.36 rear gear. :D

Can't tell ya on the track results.But gas milage is ALOT better...

graemlins/waving.gif
Rick

typically track times seem to suffer slightly with the OD trans vs a th350. they're heavier, take more power to turn, and the spread between the gears is also costly in drag racing. whatever you gain in first gear if you can hook it, you usually give back more between 1-2 and 2-3 shifts. great for a street car, not ideal for a race car. .02