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veinbar · 08-17-2011, 02:34 PM

Yes, it makes a difference. You will need a 2wd trans. Upgrading the transmission is only one element to this O/D equation. More than likely you will need to rebuild or replace your rear end so that it has proper gearing for an overdrive transmission. I am undergoing this mod right now, and it is expensive. $1000 for the rear rebuild, and $1500 for the 700r4 rebuild and install. Not to mention you have to get a driveshaft because your TH400 has a yoke and the 700r4 doesn't.

In the end, overdrive + proper rear gearing makes for a more modern / efficient vehicle, but it comes with a price tag. Like I said, I'm going through this process right now, and I cannot wait to see and feel the end results.

08-17-2011, 02:34 PM	#2
veinbar Registered User Join Date: Mar 2007 Location: Austin, TX Posts: 292	Re: 700R4 Questions Yes, it makes a difference. You will need a 2wd trans. Upgrading the transmission is only one element to this O/D equation. More than likely you will need to rebuild or replace your rear end so that it has proper gearing for an overdrive transmission. I am undergoing this mod right now, and it is expensive. $1000 for the rear rebuild, and $1500 for the 700r4 rebuild and install. Not to mention you have to get a driveshaft because your TH400 has a yoke and the 700r4 doesn't. In the end, overdrive + proper rear gearing makes for a more modern / efficient vehicle, but it comes with a price tag. Like I said, I'm going through this process right now, and I cannot wait to see and feel the end results. __________________ 2008 Yamaha Zuma 50cc - Daily Driver 1979 Chevrolet Bonanza SWB; 357ci, TH400, 3.73 Posi - Daily Driver 1976 Chevrolet Sport Van SWB; 355ci, TH350, 2.73 Open - Rape Free 1972 Oldsmobile Cutlass S; 455ci, TH400, 2.73 Open - SOLD (but I still claim to own it from time to time)