I am building a 51 F1, but I have no bed. I want to start fitting the rear tires so I can shorten the rear. I was wondering if anyone could help with with the dimensions from fender to fender. This way I will know how far out the tires can go. Thanks for any help!! Mike

 

I am at the same stage with my project, so here are the measurements I have taken from a mates truck.

Fender lip to fender lip is a shade under 76" with steel guards
With tuperware guards expect about 1/2" less......if they are accurate molds!

The bed is 49" wide, but depending on your rear end setup (springs, 4 bar ??) you may need to allow for springs and such. I have my springs under the rails so I can't help with a measurement there.

Original rear end is nominally 60".

The width you need will be totally dependent on the width and offset of your tires.

For what it is worth my advise is get your wheels and tyres first, then set them on the ground with the outside to outside measurement at 73" (1 1/2" outside clearance each side) and measure between the wheel mounting faces.

Most people find this easier (less error prone!!) than trying to do the maths on tyre widths, offsets etc.

I have a 61 1/2" wide diff with 15x8 centred (no offset) rims and 275/60/15 BFG's and it measures at 50" between the tires and 73" outside-outside

So in theory that is about perfect.

I have second set of wheels that are 15x10 with 7" in/ 3" out and 15 wide Mickey Thompsons and they will also fit my setup, but only because I DON"T have springs on the outside of the chassis.......they would of course require mini-tubs in the bed

Mark

PS Those measurements are of course from the southern hemisphere!
Maybe if you hold the tapemeasure back to front they will work in the US !!
.......just a bit of Australian humor for you!

 

That is exactly what I had in mind. I have the tires, and will be getting the rims shortly. I needed to know the bed measurement (which you supplied), and now I can lay it all out and measure for my rear.
I am going the pro street route... Big 33x21.5 Mickey T's, 9 inch rear, and a blown 460/c6. I'm not too sure if I'll need to back half it or not, won't know until I get it laid out, and see where the tires sit.
Thanks for your help Mike

 

I just did a quick calculation and I reckon you will need to step the chassis.

Standard chassis is 34" wide + 2x 21.5 makes 77" without allowing for any clearance........TOO WIDE

Allow for minimum 1 1/2 each side with MT's as they move around lot's with the low presures you will have to run under a pickup

My guess is you need to step the chassis 3-4" per side, and will also need a fair kickup to get it too sit low with 33" tall tires.

Good luck in wet weather! I use to own a pro street '56 and even with 17.5 MT's it was bloody scary on a wet road.......and that was only with a clunker 351W that would be struggling to make 220HP......I've mostly given up on real big rubber, and will only use my 15" MT's for rodrun kroozin

Mark

 

Thanks for the help, I figured I would have to step in the frame, just wasn't positive. I don't plan on rain ever being a factor, if you know what I mean. But thanks for the concern. Why do you have to run low pressure in the M.T.'s?
Mike

 

My experience has been that with normal presures in them you end up with a rock hard ride and really nasty handling, like skipping around on road iregularities and trying to step out on you in corners....even in the dry

I found I had to drop too about 14-16PSI on the F100 to get anything resembling a good ride and handling.

I guess the fact I was using it as everyday transport and the crappy roads here (compared to what I saw when I lived in CA for a while) are a factor.

I am heavily involved in Hot Rodding and almost all large tyres, but particularly MT, are routinely run at 14-18 PSI to get reasonable ride/handling.

Pickups tend to be worse than most vehicles for this, because there isn't much weight in the back end.

Most pro-street pickups I have seen end up being fair weather, fairgrounds kroozers, with ocassional highway use.

This is why I am setting up my rear end so I can have smaller radials for normal street driving, and wide MT for pose value when I want it

The trick is in the wheel offsets. A wider rear end with small centred wheels for street use and big inward offset wheels for fairground kroozing should give you the best of both worlds.

I have always subscribed to the theory that if you want a car/truck/rod to look and sit right then you buy the wheels first and set the car up around them. That way you don't have to compromise on ride and handling to retro-fit the look you are after.

Don't know if my ramblings are of any use to you!

Happy trucking

Mark

 

Thanks for the insight! I had no idea, I'm sure that'll save me some time trying to figure how to make it ride good. I am doing exactly what you said, I have the tires and the look, now I have to build the truck to fit! Someday I'll be able to drive it to the shows and just sit back and enjoy what I built.....

Thanks again, and good luck with your project!
Mike