Originally Posted by wwb
Unless you're into street racing, or plan to take it to the dragstrip, forget about it, and put the stock cam and lifters back in (provided they're in good shape).
A high-performance cam & set of lifters will give you more power, but the driveability will suffer, and your fuel economy will go right down the toilet. If you're pinched for money right now, the last thing you need is worse mileage with gas at $3.50 per gallon.
That's not necessarily true. There are cam's for heavy duty applications such as RV vehicles, wreckers and vehicles that haul or pull heavy loads. These cam's would produce greater low end torque over stock and still retain good idle & drivability.
If you have a manual transmission I recommend using a stock cam but if you have a automatic in that F-350 then I recommend a RV/Heavy Duty cam if you do alot of hauling or pulling.
If you plan on buying a new cam discuss it with the dealer and they will make sure you get the right cam for your needs.
Also if you go back with the old cam be sure the lifters go back in their original locations as you will end up with premature cam & lifter failure.