I want to improve towing performance (heavy toy hauler in the Colorado mountains @ 10K+ elevation) and I would like to add both of these upgrades at some point, but can only do one at a time. Any opinions or experience on which would make most sense to do first and follow-up with the other in 6 months or so?
P.S. I do need to replace my stock air filter very soon...
P.S. I do need to replace my stock air filter very soon...