I’d take a newer, lower mileage gas heavy duty or even 1/2 ton over an older diesel without hesitation. Pretty much any of the newer HD gas engines should pull 4K likes it’s not there, plus be a hell of a lot more comfortable than an older, smelly diesel and should go 200k without any major issues.
I don’t know what year 5.3 but if tied to the old 4 speed I bet therein lies the issue. I just don’t see a diesel being the answer to your problems
Last edited by ajmorell; 07/21/20.
