Swapped in a built 4r70 with circle d converter this past winter. We’ve been plagued with rain on the weekend for the past month or so and I’m itching to try out the new setup. I’ve put maybe 100 miles on the car since the swap on city streets, just to check manners, leaks, lockup and stall speed. I’m interested in how you racers break a new trans in, if you even do. It’s a 90% strip car, and fuel is $13.75 a gallon.