Picked up a 03 last year with basics, 2.81 upper, exhaust and a jlt ram air with a diablo predator tune. The previous owner didn't install a larger idler pulley so I got a billetflow 100m that I'm gonna put on with new belt for better belt wrap around pulley. Will I need to get it retuned, plan to in the future just for peace of mind but wonering if I should hold off installing it until I put it on the dyno or should I be safe?
