I am taking a 351w from a 93 F150 and using it to replace my tired 302 9n my F150. What can I do to get more hp and torque from the 351w? Thought about gt40 heads but wasn't sure if they would work. Also going with a rv cam. What should I do while the donor motor is out before putting it into my truck. Wasn't wanting to do a rebuild just yet. Also I will be taking the 4x4 running gear and putting it my truck. Any help would be great. Thanks.

 

Moved to proper forum.

 

As far as power in the 351, you can do any number of things, heads, cam, intake, headers, upgraded ignition, etc etc. The 351 and 302 use the same heads, so virtually any 302 head will fit a 351. The only difference is that the 351 uses 1/2" holes for the bolts, the 302 uses I think 7/16ths, and it has a special bolt arrangement for that 1/2" hole already in the heads.

I would look into getting a custom cam rather than just buying an RV cam. They're not expensive or difficult, and you'll get what you really want. The cam is the brain of the engine, it has a lot to do with what kind of hp/tq the engine makes.

Do a compression test on the motor, see what kind of compression you've got. If it were mine, I would disassemble it to install ARP rod bolts, hone the cylinders, and install new rings. I'd do something with the bearings depending on their condition. It's good to do what you can while you have it out of the truck, and having a solid bottom end before putting it in, is a good idea. You may prefer to leave it as is and rebuild it later, but thats a lot more work. Atleast check the compression to see if it's decent.


If the motor has good oil pressure at idle when warm, the compression is 150ish or higher (higher the better), and compression is even (all cylinders close in pressure) than the motor is decent IMO.

 

Is honing something I can do? I've seen the stones that go into a drill. Is it a good idea to spin the crank and put it back in? Where can I get a custom cam?

 

You can call comp cams, they will easily help you with a cam selection. Just tell them what your trying to work with and they can walk you through it.

I believe the honing process would be something you can do. I'm trying to find a carquest article I read a few months ago. They had a used mustang 5.0 and since it wasn't in that bad of shape, they just honed it and put new rings on it to restore compression. But I forget whether or not they put new bearings in it (probably did). Either way, they didn't fully rebuild it, they just "cleaned" it up a little. Their goal was to make 400hp on the stock cam with I think 165cc AFR heads.

 

To "clean up" the motor shouldn't be too expensive should it? And if you can find that article or any other tech article on honing that would be great. Thanks.

 

what year rig is this going into? cam selection will be based on what type of system it has. either carb, efi speed density or mass air. speed density system requires a cam with no less then 114* lobe seperation otherwise it wont run correctly. a good cam for a 5.8 is 35-255-5 and will run on a speed density efi system

 

You'd only be doing a partial rebuild (for the bottom end I'm refering to), so it wouldn't cost much because you're not replacing most/all of the rotating assembly, or doing any block real work/machining.
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You would need to check the wear on your block to know it you could get away with just a hone. If you can't feel any ring lip at the top of the cylinders then a honing is ok. It there is a ring lip then boring may be needed. Depends then on how much wear there is. If you have never honed a cylinder and replaced rings before, then read up on the subject before attempting so you can make sure you get a proper cross hatch on the cylinder walls. Otherwise the rings may not seat properly.

Parts wise, you can get a re-ring kit from Summit with the rings bearings and gaskets for about $175 plus you should get a new oil pump and timing chain set. No need to refresh the rings, then later need to replace the oil pump or timing chain.