2003 Suburban Z code (L59 flex fuel). I use it for towing my wakeboat and it definitely struggles to tow my 5000 lb boat/trailer at my elevation here in Colorado Springs. Looking for mods to give it more low end. Is there a cam that would give it more noticeable low end or should I put my funds toward a newer truck with more power all around? I’m mechanically inclined and work on my own cars, and would be willing to put in a better cam if that would solve my problem. I see a lot of dyno improvements come at higher rpms which is not helpful in my case. Appreciate any suggestions.