Hey Guys!
I may be blind, but I have been looking around for some ideas and am coming up short!
I have a 93 F250 w/ 174k on the clock. I have NO idea if the engine was ever rebuilt, or the tranny for that matter. It does run pretty good though.
I have owned quite a few 351s in various F250's and have never been pleased with their towing ability. Of course I came across a deal for an F250 and it had a 351 in it. I bought it...it was too good of a deal to to let go. Anyhow, I am looking for a set of heads and cam, maybe some other bolt-on mods that would wake this thing up. What would you guys recommend for a head/cam combo that I can slap on a stock bottom end? Any bolt-on mods?? TB, MAF, CAI????


Thanks for any input
Skip

 

Hello, what's the intended purpose of your truck? From your message I will assume a tow vehicle. With the amount of miles you have, I would start from scratch with a good junkyard long block. The reason for doing this is ring seal, and bearing wear, and to avoid down time on your vehicle.
Get the block baked, blasted, checked, and flat decked. Bore the block if you want or need. If the cylinders are in good shape, you might be able to just rehone them, and get new rings (maybe with the money you saved by not boring and buying new 351 pistons, you can get that 393 stroker crank, it uses standard 302 pistons, and your 351 rods). After all the machine work, have the cam bearings installed.
I would get the crank blueprinted, balanced, and polish the journals, just make sure you have the right flexplate for your torque converter. When assembling the crank and bearings, Plastigage everything for the correct tolerance. Get a new oil pump, I've been told a stock ford pump will create more than enough pressure (I've always gone the high volume route).
Building a towing engine requires a fairly short duration cam to keep the power where you will need it, down low. A roller cam might help to smoothen things out, and free up some power, but I wouldn't go over a 220* @.050 and .5 of lift, but the guy to ask is Ed Curtis http://www.flowtechinduction.com/ That stroker crank would be a definate boost to the torque numbers.
As for heads getting the stock ones ported and polished, with a good valve job isn't a bad idea. If you don't have to worry about emmissions, get them shaved a bit to bump the compression to about 10.5:1, and get them O-ringed to use the fel-pro lockwire head gaskets. Otherwise I wouldn't go over 185cc, might lose some port velocity/power at lower RPMs.
With the intake, maybe get it ported, but at least port match it. you're biggest hold up there is the stock airbox. Change to an aftermarket ram air box, you'll notice a big difference with just that on your stock engine now.
Be sure to keep things cool, get an oil cooler, and a tranny cooler(a big one for the overdrive tranny).
If you have that overdrive tranny, those things suck up alot of power. To regain some power, if you have a visor over your windsheild, get rid of it, looks good, but sucks up power. Get rid of the smog pump, and toss the clutch fan(check this out https://www.ford-trucks.com/dcforum/DCForumID18/1924.html ). I even built my own alternator bracket with a slotted adjustment to get rid of to idler pulley.
Be careful because you don't have too much of a choice but to run the stock computer because of the tranny. You can get a chip, but there are limitations to that too. I was able to toss my computer, and got rid of my fuel injection. The engine I rebuilt was out of an 80s Mustang, and I pull a 10,000lb boat with a camper in the bed. I'm switching to a stock 4bbl intake to hopefully drop the power band(just hoping I didn't cam it up too much).
That's my input, good luck.


'85 F150, low 1st 4spd,
B&B 5.0, P&P stock heads, Crane roller cam, Edelbrock RPM intake w/1'spacer, Holley 600,
dual exhaust w/ crossover, H/D radiator w/ electric fan

 

GT40p heads and compatible headers, convert to a roller cam, lift and duration like the Lightning roller cam. Zero deck the block, use thin (ROL) head gaskets and a street port/valve-job on the heads. And look into re-tuning the computer to take advantage of the need for less spark timing. Seems like if you stroke the engine, you'd have to re-tune the computer anyway.

 

Thanks!
Good thing is,,,,I have a spare 351w from my 90 F250. Maybe I should strip it and bring it to the engine shop for a rebuild.
Thanks again.

Skip

 

A 351W in stock form is no tourque monster to start with that's why you have problems towing. I have a lifter 86 F-150 4x4 that i use for just about anything from freeway driving to car hauling. I am very pleased with the motor after i did the following mods.
I started with a 79 351W and had it bored 30 over the crank turned. cleaned ect.. Anyway.

I stuck with the stock heads and ported them, but a really good choice for heads are the GT-40P head you can get them brand new for a good price.

The cam I chose was a Comp. Cams Xtreme Energy 250 cam. My truck has more get up and go than my buddy's 460 while fuel milage doubles that of his truck.

I have four-barrel intake and a Carter AFB 625 CFM carb on it and it runs well.

KB pistons, and Comp valve springs and pushrods.
My motor runs well and has substantial power and economy compared to going to more cubic inches. IE. I can pull my car trailer with my car on it at 65 to 70 up any hill and the combined wieght of the combo is about 12000 pounds. So the 351 does have tourque potential, just not right out of the box.