4L70e or built 4L60e?

[ls1k5]

I have a K5 Blazer that I put a 2000ss Camaro LS1 in with a 1999 Tahoe 4L60e 4x4 transmission in it. It's been ok for 40000 miles but the 2-3 shift has always been a bit mushy, the tranny cooler line blew off recently and after repairing it I drove 50 miles and then no 3rd or 4th gear. The fluid now looks like pearlescent paint so I'm guessing a clutch pack or band went away. I'm wondering if I should get a used 4L70e out of a Vmax, a new GM performance 19260961 trans or build my 4L60e. Any advice would be greatly appreciated BTW the LS1 is basically stock.

[pajeff02]

A fully built and reworked 4L60E can work really well -- we have one in our Trans Am from Performabuilt that we thrash on a regular basis. If you want to up the ante - a 4L80E, basically a modern version of the Turbo 400 with overdrive, is a real good choice as well, even in stock trim.