The Final Word
Upgrading our '68 pickup to an Overdrive transmission couldn't have been easier, unless we had someone else turn the wrenches. The 2004R from California Performance Transmission works great, shifting smoothly under light throttle and barking the tires under full throttle. Not only did we get a performance upgrade, but we also received one more gear for highway cruising.

Transmission lengths from bellhousing to tailshaft

POWERGLIDE
Short tailshaft 26
Long tailshaft 27
TH350
Short tailshaft 27
Long tailshaft 30
Extra-long tailshaft 34
TH400
Short tailshaft 27
Long tailshaft 34
Extra-long tailshaft 38
2004R
All 27
700R4 and 4L60
All, except Corvette 31
Corvette (1982-1996) 30

GEAR RATIO COMPARISONS
TRANSMISSION 1st 2nd 3rd 4th
Powerglide 1.76 1.00    
TH-2004R 2.74 1.57 1.00 0.67
TH-350 2.52 1.52 1.00  
TH-400 2.48 1.48 1.00  
TH-700R4 3.06 1.62 1.00 0.70

If you had 4.10 gears in your rearend, your final drive ratio would be:

TRANSMISSION
Powerglide 4.10
TH-2004R 2.75
TH-350 4.10
TH-400 4.10
TH-700R4 2.87

SOURCE
Drive Shaft Masters Co.
www.driveshaftmasters.com
California Performance Transmission
Huntington Beach
CA
800-278-2277
www.cpttransmission.com
Early Classics Enterprises
www.earlyclassic.com