so i am working on putting a 5.9 cummins in my 1994 gmc k3500 building my transmission now,
the donor transmission is a 1999 dodge nv4500, input shaft and countershaft are boogered. so i wanted a 1 &3/8" input anyway.

best aftermarket countershaft?

will the mainshaft for the gmc work ? can a transfer the gears off the dodge shaft to new gmc mainshaft, or do i need new gears? i want to keep the gm transfer case for the speedo input.

Thanks, Chuck