Adding overdrive to a TH350?

[joe231]

Originally Posted by 68GMCCustom

....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.

depends on which length TH350 you have.....the 200-4R is very short.
there are 3 tail shaft lengths available on a TH350. 6", 9", and 12".
the 700 is very close to the same length as a mid length tail shaft equipped TH350. the 200 is very close to the same length as the short tail shaft equipped TH350

[qu1cks1lver56]

Originally Posted by 3r!c84

all maters about gear ratio ,my th350 screams down the highway at 75mph @3000rpm thanks to the 3.42 gears

haha 3.42's is what I've got. 75 is about 2700rpm for me. which is great for no overdrive, but I'd really like 3.73's and an overdrive.

Originally Posted by joe231

depends on which length TH350 you have.....the 200-4R is very short.
there are 3 tail shaft lengths available on a TH350. 6", 9", and 12".
the 700 is very close to the same length as a mid length tail shaft equipped TH350. the 200 is very close to the same length as the short tail shaft equipped TH350

didn't know this, I thought it was only long or short shaft TH350's.

[3r!c84]

[QUOTE=qu1cks1lver56;3893899]haha 3.42's is what I've got. 75 is about 2700rpm for me. which is great for no overdrive, but I'd really like 3.73's and an overdrive./QUOTE]

how can i test to see if my lockup converter is working ?

[qu1cks1lver56]

Originally Posted by 3r!c84

how can i test to see if my lockup converter is working ?

only way i know of, is to unhook the vacuum switch, and run down the highway and see if you have any higher rpm's than normal, then hook it back up and see if its any different.

[Conundrum]

Originally Posted by joe231

depends on which length TH350 you have.....the 200-4R is very short.
there are 3 tail shaft lengths available on a TH350. 6", 9", and 12".
the 700 is very close to the same length as a mid length tail shaft equipped TH350. the 200 is very close to the same length as the short tail shaft equipped TH350

Forgot all about the different tailshaft lengths.