Got a rebuilt tranny with a 2500 SC and a shift kit. never had a SC before but familiar with a shift kit....never both. When I'm dogging it around town, it slams HARD into 2nd and 3rd, almost like I got hit from behind standing still. When I step on hit hard, It shifts smooth and hard, get a chirp and sometimes tire spin on slick days. Is this normal? Should I be looking for any long terms effects on teh motor or tranny mounts?