A pre-73 Ford f-150 9" is about as close as you're going to get to a direct bolt in. If you can scrounge up a set of spring/shock brakets from a '48-52 F-2 you'll have it made. The OD of the newer 9" is very close to the F-2's. You might have to get a longer tranny yoke. This should help: http://fatfenderedtrucks.com/rearaxle.html
Like bobj49f2 said. The pre 73 Ford pickup rear is a bolt in. The center section is shorter then the stock rear and the drive shaft will need to be longer. The last one I did had a 302 with a C4 and a 9 inch rear. I ended up with a drive shaft out of a 78 fairmont 4 door.
Direct is a relative term....if you find a 9" from a 57 to a 72 F100 pickup it'll bolt directly to your stock springs. You'll have to do something with shock mounts. The F100 mounts on the axle that you find don't line up with the stock F1 upper mounts. One fix is to cut the F100 mounts off the axle and weld new ones on in the right place. Another way is to get some spring mount plates that have a shock stud attached (you can get these at Chassis Engineering for around $40). You have another option. Look for a 95 or newer Ford Explorer rear end. It is an 8.8 inch unit with disk brakes already in place. Around here, the Ford truck wrecking yard sells the complete unit for $400. It is a toss-up to find an old 9" which you'll probably have to go through. The 9" is a good do-it-yourself unit, but the bearings and seals for an open diff (non-posi) rear end will set you back $200. Add a brake job and the initial purchase of the axle & you're probably over $400. The Explorer axle spring plates will not bolt directly to your F1 springs, so you'll have to cut off the plates and weld on plates with the right pinion angle. You'll also have to mess around with shock mounts. Dan
I have a 49 F1 i think had a spacing (backing plate to backing plate) was something like 54.5 inches or so. I know a few of the mustangs had axles that fit. My new IFS have chevy bolt patters so i went with a 91 trans-am rearend. I did a whole buttload of work before i kicked myself for not going with a 9" off an f100.
I used to say I agreed with the 60's Ford truck 9inch route, but a friend of mine is building one using a 8.8 Mustang rear. It came with a factory locker and disk brakes. I believe he's running an "8 inch steely with 7.50 WWW The Explorer rear end is an 8.8 as well. Their plentiful with lots of gear options and you won't have an arm and leg in one. I think my buddy paid $200.00 for his, and $200.00 for a set of used factory gears installed. TR
Here's a link to some very good information on axles swaps for early Fords: http://www.ford-trucks.com/article/...F1_and_F100_Rear_Axle_differential_Swaps.html
i am still running the original rear end in my 48, with a 5-speed out of a 1988 3rd gen. camaro. at 65 miles an hour, i am turning 2000 rpms. i lowered mine with a sids 3" dropped axle, 2" reversed eyes monoleaf springs on front, in rear i removed every other spring. it dropped my truck a total of 6' in front, and 4 in rear. the only problem i have, it is hard to get a floor jack under it, but i figured it out. i can honestly say, i have had NO issues with bump steer or any bottoming out. we are getting ready to build one for my son, and we will do it the same way. if you run an automatic, you will need another rear end, simply becaus there is no gear sets available for this rear.
I have a ‘49 F-1 and found soumeone selling an old Bronco 9” rear End does anyone know if this would fit just like the older F100 9” does on the F-1 pickups? I rebuilt the original rear end and it’s just not geared low enough for highway speed even with the 3:54 ring and pinion. Thanks.
This has been shown a number of times but is a popular chart. http://www.carnut.com/specs/rear.html It shows the 66/77 Bronco at 58 inches and the 57/72 F100 at 61.25 You would want to measure your wheel mount surface to wheel mount surface you have on the stock rear to compare.
We use explorer 8.8 rears. Shock mounts and spring pads will require some effort. Cheap way to get a posi and usable ratio inexpensively. We run AOD or T5 transmissions.
Does anyone know how much hp an 8.8 will take? I have a 351w that is 472hp at the flywheel, and will be mainly street. I'm also having an AOD from a 1990 F150, built by a local performance trans shop. Should be a fun play toy but I too am looking for rear end swap options.
That will depend on how sticky your tires on and how loose your torque convertor is. Big RPM clutch drops with sticky tires are what kills rear ends. Autos absorb alot of those big spike loads.
This is old, and was asked before, but is the offset differential of the 8.8 an issue on the F-1 I'll be getting a 1948 Truck soon. Marty
Put a 8.8 from explorer in my 53 studebaker pickup. 3.73 limited slip and disc brakes. Just had to relocate spring mounts. Worked out good.
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