Whats the 1st gear in the trans? 3.10? You can use a 4.10 with that cubic inch.
2.92
That's a lot of SLR.
Stick car is very different than a Auto when it comes to SLR. The trans was supposed to have a 2.88 first gear, but when it arrived, it had a 2.92. If the 4.56 doesn't work, I'll switch to 4.10's.
