I talked to my friend that i bought my f -3 from.he said 45 mph tops (v -8,4.86 gears) ,but he was running 26 inch tall tires (g -60 15s,yes -15s,aftermarket white spokes) I am not interested in interstate speeds,but would like to run 50-55 without blowing the engine.can i step up in tire size,within reason,and accomplish this?

 

26 inches is a pretty short tire for your application. The stock size was closer to 32". And 50-55 was about top speed in an F-3, so you're probably right in the ball park. To make it a more comfortable driver, you can change the tires to something taller, and perhaps consider an axle swap in the future. You can pick up a 60's model F-250 Dana 60 with 3.54-4.11 gears and it would bolt right in and help a lot.

 

What year is your F-3? If you have a late '51 or '52 you'll have 12" rear drums that will accept normal F-250 16" wheels and tires. The stock F-2 wheels are 6" wide and will take a 7.50 x 16" tire that measures 32'. Many later stock 16" steel wheels are up to 7" wide and would take a metric sized 235/85R16" tire. They approach the diameter of the stock 17" widow makers that used 7.50 x 17" tires that were close to 34" tall.

If you have a '48 to early '51 F-3 you'll have the old 14" rear drums that have the parking brake at the backing plates. Normal 16" wheels won't clear those drums which might be why you have those white spoke generic wheels. There are three replacement options we've identified, besides the axle replacement that Wayne mentioned. The best option, but hardest to find, would be the 19.5" x 5.25" tubeless wheels first offered in 1956. These use 8R19.5" tires that are about 33" tall. Another good option are the 17.5" x 5.25" tubeless wheels that were also available as an option starting in 1956. These use 8-17.5" tires that are about 31.5" tall. The third option, but expensive, is to have the centers of stock widow makers pulled and remounted in new tubeless 17" outer rims. This gets you back to the stock 34" outside diameter wheel and tire. Stu

 

Thanks for the input.my truck is a 52,so more options exist.I am not above a axle swap,just hoping to put it off.I have a 14 bolt,do not know the ratio yet.Would a 4:11 gain enough to justify the swap? I am not road ready yet,just looking ahead.

THANKS

 

Best to check axle width on the 14 bolt, might be too wide. The easiest fix to achieve the small increase you're after is a swap for 1997 or earlier F-250HD 16" wheels with the 85 series tires. Probably could find wheels and tires together at a local yard. Stu

 

Stu,

Aren't post '72 rear axle a little too wide to fit under these trucks? I thought the general consensus is '72 and down, I know that's the standard for the F-1s, I'm pretty sure that true also for the larger trucks.

 

As a general rule yes, but iirc a long time ago Oilyowl did a study and found that cab/chassis F-250 axles up to '75 were the same width. I thought you'd archived that info. Is that wrong? Is your question related to the p.m. I redirected to you earlier today? Stu

 

Whatever you do I wouldn't recommend running your engine at full speed for long or far.

 

Stu, I don't remember that. I just assumed because the width widened in '73 all models got wider.

Just an aside, some years ago I drove my F-2 with stock flat six and four speed to Iola, about 125 miles one way. My wife followed with the daily driver. I have over sized tires, 16X7.50, originally it came with 16X6.50, I think. We took all the country roads, a voiding the high speed state expressways. I tired to keep speed down to 40-45 mph. I know my speedo is a bit off because to the taller tires so I tried to guage the speed as best as I could. Half way through the trip I stopped in a small town for gas and my wife asked why I was going so fast. She said most of the trip I was doing 50+ through 45 mph zones. The truck didn't seem to be protesting at all. I do know it doesn't like to go faster than 60, it'll start howling like crazy, but it seems rather easy to do 50+.

 

Hmmm, my laptop is in the shop on life support again so I can't check my own archive. Stu

 

I have measured the 14 bolt,1.5" overall,or. 75" per side.I think it would be doable,if the gears are worth it.

 

The 72 and earlier Dana 60 is bolt in. I'd sell the 14 bolt and get a Dana. The 4.11 gears are worth it. With a 235 / 85 R 16 tire (30.39 inches tall) at 2700 r.p.m. you go from 50 m.p.h. to 60 m.p.h when you switch from 4.86 to 4.11.

If you really want to get going down the road, find a Dana 60 with 3.54 gears. With 3.54s and the 235 /85 R 16 tires at 2700 you get 69 m.p.h.

 

I don 't know about 69 mph on drum brakes and straight axle,but i will keep looking.Checking the gears on the 14 bolt this wekend.

 

Kids. No sense of adventure.

That's what some of us grew up on, 'cause that's all there was.

 

I am 46,hav drove dump trucks that fast,also drovre some pretty adventureous rides.guess i am just getting old,but i am not growing up!