need 8 1/4 advice

i think your right, i just searched a ring and pinion set with 3.90 gears and can get that for 200ish with install kit. just need to get in the cover and confirm that i have 2.7 and higher carrier. if it turns out that i have a suregrip carrier, can the springs be adjusted? the evidence marks on the road dont appear to be 'suregrip'. with your gear change, how was it mechanical wise? i dont know any of the tolerances inside the rearend housing.