TH350 to 700R4 Driveshaft

[bad72c10]

Hey guys, I have a TH350 with a 9" tailshaft in the truck now, so I should be able to reuse the driveshaft for the 700r4 with no modifications, correct?

Also, when I look up a transmission mount, it has three holes, yet the crossmember only has two, how does that work?

And lastly, does anyone know where I can get just a single speedo gear?? BTO only sells a $52.00 complete set

Thanks for your help, Justin

[dave2953]

The TCI website shows them to be nearly identical in length. Your trans. is 30 11/16 and the 700R4 is 30 3/4, so you should be able to use your current driveshaft. I'm not sure about the mount or the speedo. I'm sure someone else will chime in and let you know.

[lamar]

I went from Turbo 350 to 700R4 and I had to have my drive shaft cut and rebalanced. Also had to relocate the trans mount.

[Mixup]

I had the 9" tailshaft 350 and the shaft worked fine. The speedo worked to just had to change the gears to match the tire size and rear ratio. Crossmember has to move back to match the 700r4 mount.

[bad72c10]

Thanks Mixup, I was sure it would work, but it is good to hear from someone who has done it. I knew the X-member had to move back, but the holes where you bolt the tranny mount to the x-member has 2 holes, yet the mounts that I see have 3 holes for bolts. does it work anyway?

[cooters]

just go to a tranny shop, the mounts come in 1 ,2,bolt holes or even a stud. Get the one you need from the tranny shop is usually the cheapest and they should stock them all.

[Mixup]

Mine has the 2 bolts that hold the mount to the trans and 2 bolts from the crossmember to the mount. You might have to get a different mount.

[BACKYARD88]

You should be able to buy the speedo gear from a GM dealer individually.