TH350 vs. 700r4

[Chevelle454]

I am swapping out my 305/700r4 in my '84 Caprice to a 355/TH350. What will I have to do to get this tranny to hook up? I imagine that the trannys are not the same length...

[72GMC51]

Try this site it pretty well covers the bases. http://www.oldengine.org/unfaq/leadfoot/th350in.htm

[SweetandLong68]

Definetly not the same length T350 is quite a bit shorter than the 700R4.

lata
CHRIS

[Tx Firefighter]

Originally Posted by SweetandLong68

Definetly not the same length T350 is quite a bit shorter than the 700R4.

lata
CHRIS

Not necessarily. There are 3 different lengths of turbo 350 transmissions, the 6 inch, 9 inch, and 12 inch tail units. The 9 inch was very popular in the late 70's and early 80's. The 9 inch is coincidentally the same length as a 700r4 is. It will all depend on which length 350 he has now.

I swapped a buuunch of early 80's pickups from overdrive to turbo 350 because the owners were tired of the failure prone early overdrives. The swap was easy because the driveshaft and yoke interchange freely between the 2 transmissions.

[72GMC51]

The drive shaft I am using is out of a 71 chevy long bed that had a long shaft 350 and it fits like it was made for the 700r4. I bought new trany lines for a 350 and with very little bending they hooked right up. I used an after market trany mount which bolted directly into the holes in the frame, a lockar linkage and used the bow tie overdrive tv made easy set up which I am in the middle of doing right now. They use the same setup to lock up the converter as advertised by Sallee Chevrolet, you can go to salee-chevrolet.com and look under GM tranys, they sell the trany I am using and have complete instructions you can print out. The truck I got the drive shaft from had the 9" tail shaft which is the middle size not the longest.or 12"
Hope this helps

[SweetandLong68]

Originally Posted by Tx Firefighter

Not necessarily. There are 3 different lengths of turbo 350 transmissions, the 6 inch, 9 inch, and 12 inch tail units. The 9 inch was very popular in the late 70's and early 80's. The 9 inch is coincidentally the same length as a 700r4 is. It will all depend on which length 350 he has now.

I swapped a buuunch of early 80's pickups from overdrive to turbo 350 because the owners were tired of the failure prone early overdrives. The swap was easy because the driveshaft and yoke interchange freely between the 2 transmissions.

You are right... The different tailshaft lengths didn't come to my mind when I posted that...But yes you are exactly right. My appoligies

lata
CHRIS