Any issues (besides driveshaft) in mounting a long tail TH400 in a 1970 Cutlass? Any crossmember, speedo issues?

 

Propellor Shaft Alignnment
Review pages 4A-3 onward in the 1970 Service Manual.

Short extension (group 4.317) is for Cutlass. Long extension is for Vista Cruiser. Longer extension is for Cadillac.

 

I ran a long shaft turbo 400 from a 68 Delta in my 70 Cutlass. I put a shift kit in it, installed new chrome pan and gasket, I replaced the front and rear seals and had the driveline shortened to fit. After I had it installed I realized there was no provision for a speedometer on the transmission.

 

The 1965-70 Olds full size cars drove the speedo from the left front wheel. Transmissions from those cars typically do not have any provision for driving a speedo. The case is not machined for the speedo gear adapter.

 

Is the boss there if one were to retrofit?

 

You would have to completely disassemble the trans and have the hole bored with enough control on tolerances so that the O-ring on the adapter seals.