5.4 with some minor upgrades will pull good! What are you pulling?? diesel if your gonna pull a skidsteer. Every lawn you stop and go, does a diesel like that?, LOL! To me diesel suck bec when it breaks down you are F*****! Time and money. If you pull skidsteers and other heavy crap yes the gas will stress out and the diesel will take it pretty well but they will prolly cost the same in the long run when pulling very heavy stuff so its an even call.