Just picked up a 79' F100 with a 351w in it, previously refit.
Figured it would be quicker than it is and more hot rod. Any advice on what to look for in terms of how to get more speed and HP onto the back wheels.
Its 4x4, got 35's on er, engine is been build up and chromed out, new 750cfm carb just swapped out and reinstalled/old one was gummed up, 4 speed shifter. 1st gear is not used, too much torque, rock climbing gear I assume.
Its my weekend driver and I just want to be able to tool around and light em up when needed. But I can't get the torque out of 2nd into 3rd, and 4th is just a sleeper currently.
Any advice would be appreciated.
TY

 

351W's not installed until 1981 in F150/350 & Bronco, but not in F100's.

There were no F100 4WD's after 1976.

Post the VIN to verify what your truck is.

 

It takes a lot to push around a big heavy old 4WD truck on 35s. 750 CFM sounds a little large for a stock 351. You could grow the engine into the carb with a good aftermarket intake manifold, some good heads, and a higher revving cam. If you're on a smaller budget, look into some Explorer GT40 heads from the junk yard. I would thnk that a 351 would still benefit from the newer heads, even though they were designed for 302s.

 

IMHO anyone that would swap a 351M/400 for a 351W is ignorant or an idiot. There is a reason that we are familiar with the term clevor.

Good luck.

 

My first thought was 35's on stock gearing. and post a pic of the motor.

 

 

Thanks Guys.
My bad they are 33's
The truck has been converted to a 1ton chassis/8 lug
I just posted some Pix of the truck and engine.
351W is not stock, Alluminum manifold and edelbrock headers, with the edelbrock carb. Engine is tight, runs well, just can't seem to get real power through the gears onto the street. Lags from second into 3rd?
the dash has been all redone, so vin not showings, but title has listed as 79 F100. It's definitely not stock, original owner and his dad (buddies of mine) did all the work about 20 years ago.

 

The resto has certainly held up. Good looking truck.

As others have said, the bigger tire and those heavy wheels won't translate to hotrod performance.

I would start checking the timing and retune the carb. Edelbrock has the manual on the website. you can move the accelorator linkage to get more fuel or less when you hit the throttle, try moving a notch to change the stroke. Check your floats, maybe they are set too low.

Check your plugs for fouling or pitting. Find out if its getting enough or too much fuel. Check the gap too.

Check your ignition wires for resistance. If it is an old resto, things might not be up to snuff.

Take the cap off and clean that distributor, could be getting poor spark from corrosion.

You could try using the manifold vacuum port on the driver side of the front of the carb for your vacuum advance. The driver side pulls manifold vacuum and, tuned/timing set correctly could provide better response.

These are all things that don't cost money and will help you get to know your truck better. From there you can start to consider "upgrades".

Also make sure those brake hoses are not rubbing on the steering shaft. You might want to secure them better. And it looks like your brake booster vacuum line is hooked up to the pcv port on the carb. You need full manifold vacuum which is from the back port of those carbs only.

And I cannot tell what your pcv is hooked up to, but you might want to hook that up to the front of the carb where it is meant to be. Not ideal to have full manifold vacuum on your pcv.

 

I'm going to go out on a limb and say that's a 351M/400 which would make more sense. Also as far as the 8 lug wheels I'm betting he used heavy duty outer Cs on a F150 Dana 44 judging by the radius arms. If it was a F350 chassis it would probably have leaf springs out front. Non of this is bad news for you just trying to figure out what we are dealing with.

 

or it's just a F250? Post the VIN up and that should help. The only way to tell the difference between a 351M and a 400 is to measure the stroke. 351m=3.50" and the 400=4.00". My bet is it's a 351M and if that's the case find a 400 crank and get some TMyer pistons. Then you will have no problems throwing around your 33" tires.

 

Appreciate the tips Hotrod.
She sat in a shed for about 12 years until I just brought her back to life. So I figure there are definitely some items off a little due to the time she slept.

 

If it sat for 12 years check your mechanical advance. They were famous for seizing up in those HEI distributors.

 

10/4 J ballan, I'll get da vin and that's gonna tell a lot. Definitly 351W, so the 400 crank and pistons sounds like a good fit.

 

A whole lot of really good body work went into this truck. You're going to have to share more photos. I am really impressed that the filled markers were done right. Much of the 'custom' body work you see would have cracks by now. And shaved drip rails and filled the seam on the roof.

And is the gap from the cowl to the fender filled? The labour and materials that went into paint and body has got to be closer to 8-10k.

Given 12 years ago, I am surprised/thankful it has door handles.

You have a really nice truck to start with, I can't stress enough the importance of tuning and getting it dialed in.

Seems like they just kept throwing money at it until they lost interest?

edit: holy crap did they spend money. I was looking at the p/s pump, that is a fancy canned ham. Billet reservoir?

 

Your engine is a 351m or 400. A 351W looks like so. Note the water outlet in the intake manifold (where the red rag is), and the trapezoid shaped valve covers.

http://www.allfordmustangs.com/forum...inefront01.jpg

If it is still a 351m, it is making about all the power it's going to make with those add on items. Real power from a 351m requires a 400 crank and some pistons that yield compression, plus a cam.