Remembering back...I had a winters qc in the coupe...3.00 gears. After returning from the nats (12 hour run) I was unloading the trunk and leaned over to get a bag from the back. I put my hand on the un-insulated (painted) floor and...burn-baby! I reached under the car and the rear finned cover was HOT! HOT! The qc had helical gears and ran valvoline 90wt, and had a vent...so do they run hotter than a '40 banjo or a 9" ford rear? I'm trying to decide on which rear to put in my truck.