pickup track widths

[whtbaron]

    Ok, this story is a little convoluted so bear with me. I'm collecting parts for what I hope will some day be a vintage racer styled speedster. To date i have a 29 Whippet frame that I had originally mistaken for a DeSoto unit. Since Whippet was bought out by Willys, which became Willys/Overland, eventually Jeep, AMC and then Chrysler, I think it deserves a Mopar power train.

     At this point, you are probably wondering WTF is this guy doing in a Pilothouse Site? Well, I got a 228 long block flat head 6 and 4 speed truck transmission from a 52 Canadian Dodge pickup, but now I need to think long and hard about axles. Plan A was to use the truck 4 speed, some 61 to 64 Dodge pickup axles and tall wire wheels to increase the effective gear ratio.

     Not actually having owned one of these early 4 speeds before, I thought increasing the final drive would bring the granny gear first up to a decent launch speed for the light speedster body. Discussions here and on the HAMB with Fargos go Far and others have me rethinking that plan however. Maybe I should be looking at one of the adapters to go to either a T-5 or the A-833 from the get go since I will be making motor mounts to adapt to the Whippet frame anyway.

     The second and more pressing question is track widths of the axles. Does anyone know how the track width compares between the early 60's trucks v.s the late 40's early 50's units? I can find lots on wheelbases, but nothing on track width or axle width. I would think they would be similar up until the 65 run, but those 61 to 64 trucks look quite wide as well. I'm also not too impressed with the steering box being in front of the axle line. Trying to tuck that in behind the frame on a fenderless car or moving it to the back could really mess with the steering geometry and I would  like to avoid bumpsteer. My plan is to keep the dual leaf springs front and back that the Whippet had (very similar to 20's Dodges), but if this car is capable of 90 mph, it will need decent brakes and steering. I was thinking I could retain the drum brakes front and back, but hide a power booster under the floorboards.

    I'm still working on my heated shop between snow storms, so this is all very early in the planning stages. Other than accumulating parts, I don't have much other than a blueprint for a low budget,  Indy style speedster in the back of my head. Lets open this one up for discussion and see where it goes.

[Dave72dt]

58 5/8 on the front, 61 1/4 on the rear for a B108

Under the resources tab, DPETCA site, pilots knowledge - scroll down. there's a bunch of builders layout prints you can get dimensions from.

[MBF]

The final drive ratio in a 4 spd is 1:1 (same as a 3 speed).  You may want to look at a syncroed 3 speed to make the unit more driveable or like you said an A833 O/D.  Unless you put some super-high ratio rear in the vehicle, I don't believe that first gear is going to be of much use to you.  If it is, your 1-2 shift will likely be a slow one since it will need to be double clutched with a granny geared truck transmission.   Just my unsolicited input.   Mike

[whtbaron]

Thanks Dave, I'll check that out. Once I decide on a front axle, then I'll have to sort out what I want for a rearend to hopefully keep the gearing right and maintain the same bolt pattern. I've got an 9" Ford out of a 76 Granada but I'd like to keep it all Mopar and the little 6 won't need anything that stout. Another option would be to use whatever is in the parts pickup but that will likely be quite low unless I get into the 60's. The overdrive tranny starts to make sense if the rear is down around 4 to 1.

The 3 speed is also an option but then I'd likely go to something like a 52 Plymouth car rear. I can remember when everyone sold floor shift conversions for those, but finding one now might be a bit of a challenge. The taller tires would effectively raise the final ratio some, but the light car should keep it liveable. I don't anticipate a lot of extra cash going into the motor, but I will probably shave the head for starters. Listening to Fargos go Far has me thinking that the stock 4 speed isn't going to work as well as I had hoped. The crash box doesn't scare me too much, I've driven old trucks since I was 10. It's a definite disadvantage down-shifting into first, but with a little practice you can do most of the upshifting playing by ear and not using the clutch at all.

Edited December 28, 2015 by whtbaron

[Dave72dt]

If you were putting the Granada rear into a Pilothouse, you'll find it a bit narrow.  It's a rare 9 " coming out of a Granada,   A Versailles would have been more likely..  I've got a 8" out of a V8 Monarch in the back of my truck and it's going to take a deep offset rim to clear the box and still fill the fender well. The only rim I've found that will work without spacers is a 15 x 8 Cragar SS with a 2 1/2" backspace.  It does however, keep the track width within a 1/2 inch of factory specs.

 

Since you're using a Whppet frame, you'll have to get the tape measure out to see what will work.

[wayfarer]

Track width is not the same as WMS width since track width is dependent on the amount of offset in the wheel.

 

I have some WMS numbers on my web site: http://www.qualityengineeredcomponents.com/?page_id=1023

you just need to decide where the tires need to be and work backward through the wheel offset to get to the WMS number.

[55 Fargo]

Thanks Dave, I'll check that out. Once I decide on a front axle, then I'll have to sort out what I want for a rearend to hopefully keep the gearing right and maintain the same bolt pattern. I've got an 9" Ford out of a 76 Granada but I'd like to keep it all Mopar and the little 6 won't need anything that stout. Another option would be to use whatever is in the parts pickup but that will likely be quite low unless I get into the 60's. The overdrive tranny starts to make sense if the rear is down around 4 to 1.

The 3 speed is also an option but then I'd likely go to something like a 52 Plymouth car rear. I can remember when everyone sold floor shift conversions for those, but finding one now might be a bit of a challenge. The taller tires would effectively raise the final ratio some, but the light car should keep it liveable. I don't anticipate a lot of extra cash going into the motor, but I will probably shave the head for starters. Listening to Fargos go Far has me thinking that the stock 4 speed isn't going to work as well as I had hoped. The crash box doesn't scare me too much, I've driven old trucks since I was 10. It's a definite disadvantage down-shifting into first, but with a little practice you can do most of the upshifting playing by ear and not using the clutch at all.

You could try going to A833 trans, you then have overdrive 4th, and a 3.73 rear end. Or why not try that Ford 9 inch if it will fit, with your 4 spd. You will be taking off in 2nd, not 1st. I have no trouble down shifting from 4th to 3rd to 2nd, no issues.

What is the gear ratio of the ford 9 inch? There are plenty of Mopar 8 1/4s out there too..

[whtbaron]

    The Whippet frame is very similar to the Dodge of the era, somewhat larger than a Model A. It's original wheelbase is 112.5 with a 56" track width front and back. I've got a fair amount of fudge room there since I won't be running the stock fenders, but with our gravel roads I'll need to make or adapt some motorcycle style fenders to fit it. Going slightly wide will just increase stability, but I would like to keep things lined up fairly close from front to back.  With the speedster look I'll be running narrow wires, so no offset, and probably about 4" wide tires with something like an 18 or 20" wheel.

     Everything is in a snowbank right now so I'm looking at Googled numbers but the Granada/Versailles 9" is listed at 58.5" with most likely ratio being a 3.75. A 70's Mopar A body 8 1/4 runs around 55.6", but both of those rears are a little more modern than the look I want. The one in my 52 should be around 60". The biggest issue right now is finding a cheap junk yard front axle that will work with fairly modern drum brakes, and not be out to lunch with the rearend width. Otherwise I'm stuck going to an aftermarket axle that will look more "hotrod" than speedster, and paying through the nose with our 70cent dollar to get it imported and then buying all the expensive brake kits that go on it. The Whippet chassis is designed for parallel leaf springs front and back so I will most likely keep it set up that way. If I have to go to an aftermarket front axle, it would likely be easier to adapt a Model A front crossmember and go to the single leaf Ford system... another minus in my books because it takes me one step closer to a belly button car that I don't want.

[whtbaron]

Early 60's pickups are listed at 60" for the rear, but I still haven't found front axle numbers. I'll have to find one and measure it to see if it's narrower than the rear like the early 50's pickups are. Might have to update the brakes on a 50's version yet. That being said, a 60" front wouldn't be a bad match for the 60" rear axle out of a 52 car, which would also have a 3.73 axle ratio. Early 50's  Mopars used a 4.1 or 4.3 with their overdrives and had shorter tires than what I'm proposing.

Edited December 29, 2015 by whtbaron