93 Firehawk LT1 4L60.

I had the car shifting at 6375 using weights 4 and 6 (stock spring) in the governer.
We installed LTs on my car last week and to use smaller weights (5 and 6) to up the shift points a bit.

Funny thing though, when we did that I hit the rev limiter every time at
6100 - 6300.
It didn't seem to matter if I raised the constant, she just wouldn't shift.
After two sets of weights and a few chip burns, we finally just put the
weights I had previously been using back in
and it went back to shifting at 6375.

Is there another constant or some setting I missed?