55 f250 performance
Laughing Gas
Joined: Nov 2006
Posts: 1,125
Likes: 4
From: Olive Branch,Ms
Welcome to the site tsamm It does sound like it would go faster then 45 mph. Have yet to make it past the end of the driveway with my you could say I'm still in the building stage. You probably have to go over it and see what is slowing you down. Could be a number of things from old plugs and wiring to old gas.There be a few other people that will kick in to show you a few things to do and check.
Post Fiend
Joined: May 2008
Posts: 7,641
Likes: 21
From: Poway, Ca.
It may not be unusual to be slow like that - especially in the larger truck. Alot of them then were still being built for farm and plant work and thus speed was not as important as carrying ability. The 6 cylinder also had more torque than the V8s
Take a look on your glove box door for a metal plate known as a "Rating Plate" it will have a serial number, a transmission code and a rear end ratio on it. If you can let us know what they are, I'm sure someone can help out.
Welcome to FTE by the way!
Take a look on your glove box door for a metal plate known as a "Rating Plate" it will have a serial number, a transmission code and a rear end ratio on it. If you can let us know what they are, I'm sure someone can help out.
Welcome to FTE by the way!
Cargo Master
Joined: Sep 2004
Posts: 2,906
Likes: 82
From: Oregon
45-50 seems normal. My F-750 started talking back above 50, and it ran and drove like it had only 7200 miles (oh wait it did only have 7200 miles on it). Dada 55 F-350 starts talking back at around 50, and is really wailing at 55-60. 45-50 is probably all that little six is gonna do, and it's probably pretty close to peak as new too.
Post Fiend
Joined: Mar 2007
Posts: 5,776
Likes: 2
From: springfield il
like was mentioned what gears ya got in the diff ? put two marks one on the tire and one on the driveshaft , and with the truck in the air , turn the wheel one rotation and count how many times the driveshaft turns . in mines case the driveshaft turned almost four times to one rotation . hence i got the factory 3
2's in my half ton . this with the flatty will only let me get 50 - 55 without it turning so hard it sounds like she's gonna self destruct in steady state driving . my one ton 55 had 5:14's , the f600 had 8:30's in low and in the high 6something ...........
not uncommon for 'em to be slow in oe form . they can move the world in the bed , but don't expect to do it in a hurry !!!!!!!!!
2's in my half ton . this with the flatty will only let me get 50 - 55 without it turning so hard it sounds like she's gonna self destruct in steady state driving . my one ton 55 had 5:14's , the f600 had 8:30's in low and in the high 6something ........... not uncommon for 'em to be slow in oe form . they can move the world in the bed , but don't expect to do it in a hurry !!!!!!!!!
Elder User
Joined: Jul 2005
Posts: 739
Likes: 0
From: Morgantown, WV
I don't know how fast my 55 F-250 goes, but I did sit in the cab like Julie instructed me to do so, and I went VROOM VROOM to my hearts content. I must have been going at least 100mph +.
Honestly, if you need more speed you will have to swap out the rear end more than likely on the larger trucks.
Honestly, if you need more speed you will have to swap out the rear end more than likely on the larger trucks.
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Tuned
Joined: Oct 2002
Posts: 263
Likes: 0
From: ELLICOTT CITY, MD. USA
My '55 F-250 would harly get out of it's own way. If yours is like mine, it has the "Banjo style rear. Mine had 4.85 gears. It was screaming at 45 mph. I put a '68 3/4 ton rear in it and it has either 4.10 or 4.11 gears (i can't remember) and I can now get her up to about 50ish without screaming too bad. I'm told a rear end with 3.75's or lower would get some more out of her. The 4 speed transmission with the granny gear probably dosen't help either. However, the tranny is a 1 to 1 ratio in 4th gear as would be the 3 speed so changing the rear is probably the best bet.
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Tuned
Joined: Oct 2002
Posts: 263
Likes: 0
From: ELLICOTT CITY, MD. USA
There might be a tag on the rear or axel housing with a ratio stamped on it. Or, if you still have the VIN plate in the Glove box, it would be stamped on it. My VIN plate was missing. A "Banjo" style rear looks different that a newer style rear(differential). It has 2 halves that bolt together, like a banjo and the drive shaft comes out the front as opposed to a newer style with a "pumkin" with a plate on the back that bolts on. I thought I read that the banjo styles were 4.85 a ratio. That is what mine is. Do you also have the t-98 tranny with the granny gear? These are real stump pullers.
Elder User
Joined: Jul 2005
Posts: 739
Likes: 0
From: Morgantown, WV
I believe the F-250's came with either a Spicer 44 or Spicer 60. My axle has a 60 stamped on the lower right section of the pumpkin. So I think I have a 60, now what gearing it has, I don't know yet. I still have the glove box door and plate, so I will read that again tonight to see if it has the gearing on it.
Tuned
Joined: Oct 2002
Posts: 263
Likes: 0
From: ELLICOTT CITY, MD. USA
Glockem45, I looked at your gallery and you have a rear with a pumpkin. Mine was original and had the banjo style. I have a feeling yours might have been changed out at some point. Check for a plate or something stamped on the axel tube for the ratio. I have a feeling your Vin plate might not be accurate. I changed mine out to a Dana 60 which has the 4:11 gears. I get a little more spped from it before she starts screaming, but at 55 mph with the 223 straight six, that's about all I'll get out of it unless I change the gearing even more.
Elder User
Joined: Jul 2005
Posts: 739
Likes: 0
From: Morgantown, WV
The entire truck is original (supposed to be), and that Timken or Spicer 60 is the correct axle option on our trucks. Let me find the link that shows the F-250 axle options for 54-55 F-250's.
