96 5.0.. Gonna rebuild the motor come winter, so I wanna know what I'm getting into and what kinda performance to expect... So here's what's happening: 4:10 gears, gt40 intake upper& lower, e303 cam, gt40 heads, block bored 30 over, long tube headers, and pistons.. Its a 4x4 with 31x10.50's... What Should I expect performance wise? Good low end torque? Will I be able to out runs some ****?

 

Nope, not with that cam.

 

Okay well I just through out a random cam let me just as a good truck cam

 

Swap to mass air and buy a crate, less headache.
But if your going to do it yourself, grab some gt-40 heads (3-line) a good rpm band cam (idle-5500 for the tourque), rebuild kit with scat crank, or just go for a Dss short block with it ready to slap heads on and a cam.

 

Don't they come stock with mass air? I'm able to get the parts cheap so a crate is out of my budget

 

Besides that I've alread bought the headers and intake and gaskets and hoses and little stuff

 

Some motors were maf and some weren't. You would know if you have a meter after the airbox. I say once the snow flies, pull it, and tear down. First engine build? Feeler gauges, dial indicators and gauge Puddy will be your friend.

 

Well mine has mass air, but after you said first rebuild which the answer is yes you lost me.. But with the arts list I mentioned what should I expect

 

If you are committed I would say be prepared for the inevitable. New engine mounts and anything that could go wrong may go wrong, I say get the stoker kit, 331 will handle punishment all day, I stuck with a 306 base block, for simplicity, that and it was rdy to go.
But make sure when you send in the block, make sure they pressure test it and check for cracks. If its your daily, I would recommend buying a block from the wrecker and build it as you go. Something small on an engine stand to pick away at. (if I bought my motor while I was married id be 7 feet in the ground if ya know what I mean).

 

Oh and of course, the computer may have to be repinned to a mustang computer. Some tuners are sticklers on having a A9L EEC. Repinning is over a oldfuelinjection.com

 

The OP's truck is a 1996 F150.....It has MAF and OBD-II. There is NO reason whatsoever to downgrade to a OBD-I Mustang PCM.

The problem with the E303 cam is it's basic design. It's a lumpy cam that builds power in the upper RPM range by sacrificing low-end torque. Ford's "alphabet" cams were not one of their better ideas IMHO.

Paul Conanski has recommended a few different Comp Cam grinds in many posts. I'll check to see if I can a find a recent one. For that matter the factory 5.0L roller cam your truck already has is a decent cam for a truck. A change to 1.7 roller rockers will net you some easy horsepower gains for minimal $$.

 

If you want Torque then you're wasting your time with 300 odd cubic inches, you need to make it a 347 stroker or swap in a 5.8 shortblock. If however you just want a fast truck then go ahead with your plans but make it 4.56 gears and put the comp cams 35-320-8 roller cam in it.