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Old 03-30-2010, 08:31 AM   #7
Conundrum
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Join Date: Oct 2008
Location: Parsons, KS
Posts: 652
Re: Adding overdrive to a TH350?

Quote:
Originally Posted by 68GMCCustom View Post
....or try getting a 200-4r (built up of course). The 200-4r is the same length as a turbo350, has a different ratio for 1st gear(and 2nd?) for a better 1-2 shift w/o the bog, and has a slightly lower (.67) overdrive. I think (not sure) that even the spline count is the same...meaning you can use your old driveshaft. I think the only real change other then the TV cable, is the tail mounting location, meaning slight changes to your tranny crossmember. I'm no expert so I could be off on some of these details.
The trans mount is in the same place as a th400, so you would only have to move your trans crossmember back a little ways. I found this info....although i'm not to positive on the accuracy of it, I think the 2004Rs 1st gear is a 2.74. Although it came from TCIs site.

TH350_________TH400
Lo 2.52 2.75____2.48 2.75
2 1.52 1.52____1.48 1.57
3 1.00 1.00____1.00 1.00



200-4R__700R4/4L60E__4L80E/4L85E
Lo 2.78______3.06_________2.48
2 1.57______1.63_________1.48
3 1.00______1.00_________1.00
4 0.67______0.70_________0.75


http://www.tciauto.com/Products/Tech...ear_ratios.asp
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Last edited by Conundrum; 03-30-2010 at 08:35 AM.
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