I put a $30 (back in '94) B&M Stage 1 shift kit in my '79 Firebird (Olds 403/TH350). If you drove it normally, it would shift like normal. If you got on it, it would bark the tires going into 2nd (at 65) and then bark again going into 3rd (at 85). Other than taking 2 secs to drop into gear vs. the normal .5 sec., you really couldn't tell the diff. unless you got on it.

Best $30 I spent on that car. I will be putting one in my Isuzu shortly.