85 Caprice Classic Trans.replace/rebuid

I Would Like To Know What Is The Best Trans. Replacment/rebuild For A 4 Speed

Your car should have the TH700-R4 in it, though sometime around then they started using the TH200-4R in it - look at the pan - if it's square, it's a TH700-R4 - if it's kinda oblong with an angled back, and dual-sump with the smaller sump in the back - it's a 200-4R.

The 700-R4 is the better of the two in terms of making the most out of that 305 - it has a lower first gear which translates into better 1st gear torque, great for that big car. Certain year 200-4Rs are as good as 700-R4s as far as durability concerns - generally the 1986 and later ones. I'd still pick the 700-R4 (sometimes referred to as a 4L60) over the 200-4R for that first gear punch. The 200-4R has a slightly taller overdrive than the 700-R4 does.

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If you have a 200-4R and wish to convert it to a 700-R4 you'll need to get a driveshaft out of a car that has the 700-R4 in it (they're different lengths) as well as a crossmember (unless the 700-R4 you get happens to have the rare dual-mount setup in which it will bolt right up). The TV cable is interchangeable but the dipstick tube is not, so you will need one with the transmission. Don't forget to properly adjust that TV cable when you're done!