ive got a manual 95 f150 4x4 with a 4" lift and 33's. problem is i do a lot of towing with my truck and it just doesnt seem to have as much power as it did befor i lifted it. i want to upgrade my engine for more power but i dont know if i need to switch it for a 351 or if there are some other ways of getting more power without changing my engine. anybody got a suggestion?  

I'd try re-gearing it first before changing the engine. What's your axle gear ratio? How much weight, on average, do you tow?  

Gear it, then start reading up on what the Mustang guys are doing... these engines can make TONS of power... you can get pretty much anything you want for it from the aftermarket...  

well heck no ya don't have as power. you need to regear it. the 302 was never a stump puller anyway. they didn't make big torque numbers down low in the rpm's at all. but a set of 4.56 R&P's would get ya back to where ya started before the big tires.  

put a novi 2000 supercharger,an edelbrock victor intake and a .700 inch lift cam,heads with 350cc ports, four bolt mains...uhh wait, look at jegs dot and theres a buncha stuff ta make more power with,includinga 347/5.0 kit
happy wheelin!  

As someone mention earlier, the answer lies in a new set of deeper axle gears not a new engine or supercharger. When you installed bigger tires you greatly reduced towing power by making final drive effective ratio taller which increased strain on engine and tranny. Deeper axle gears will level the play field and restore power and reduce drive line strain too.