My buddy pulled his 91 two days ago. It is a F250,2wd, 4.1, ZF, 7.3. He "turned up" the screw on the pump. He hooked to the sled, and had no traction problems. He let the clutch out at 1500rpm in 1st gear and he got itmoving about 20' and about 1800rpm then it quicklt brought the 7.3 down to 1,000rpm-floored before he hit the clutch. Seems kinds weakto me it should ATLEAST spin the tires trying to move the sled. Are the IDI 7.3's that weak or did turning up the fuel screw "screw" him.
He Still thinks my 78 F250, NP 435 ,300 I6 would make atleast 100' before traction problems, but after seening that i'm not so sure.My truck should spin the tires in granny gear tied to a sled right?-maybe??
Thanks,
Dustin

 

when me and my brother used to pull we didnt want to spinn rite from the git go.on a good tight track(clay)the only time you should spin is when the sled "gets ya".we found out that granny gear was usless cuzz you cant get enuff speed out of it use 2nd low range and buzz the snot outa it

 

we found out that the 7.3 IDI will NOT even break the tires loose with 4.1's(2wd) and in low (zf5)
Do you think my 78 can?

 

that is one tired id then. I had one before my current strokers and it would spin em right over WITHOUT much grunt at all.........

 

Huh, can't get a 7.3 IDI to break the tires? My buddy's 1992 F350 dually will whitesmoke the tires if you pop the clutch right, and his motor is plum wore out.

 

nope she wouldn't break them loose on clay, this has my 300/np worried

 

Yours is 4wd, right? So put in 4-lo, and pull in 2nd. If you take off, and it is lugging, try to stop before the 75 foot mark, and you can start over. Use first then. But most of the guys around here pull like that with no problems.

 

no its 2wd, but I've seen 2wd's pull 250+ ft so it is more of atorque/gear question

 

have you played with the timming at all, or checked it?

 

im thinking that truck needs some engine work i have a 91 myself and i can get it to spin all 4 if im tied to something i cant move -not that theres much i can't move.
it can spin the rears just about anytime i want it to unless im above second.
iv got a rebuilt e40d and a tall rearend.
i hope you get that thing pulling better

 

I hope you have better luck next time. Me and and a good friend of mine both have 7.3L idi's w/ turbos and have never pulled under 210 in the single turbo class. But after the turbo my first clutch went fast.

 

Pull the 300. There are a couple of guys around here that pull 300's and they are very impressive for a 6 cylinder. I have never seen any 300 come in last unless they were pullin in the big block class. The one guy is running an 89 f-150 300 with 33" tires, posi rear and enough weight to make the 6500 and 7800 lb classes. I have never seen his tires quit spinning in the 5 years that I have been watching him pull. The motor is stock. Actually he bought the truck for $200 and just started pulling it aside from installing a mini-spool in the rear. He beats V-8's all the time. Now he has only won 1 time that I know of but everybody loves it when he comes to the line because of the big ole 6.

Oh yeah, his truck is 4x4 and a manual tranny also.