Dent 9" rear end

[FLHRC]

I have a '77 donor truck and am thinking of overhauling the rear end and rolling it under the '72. What modifications will I have to do to make it work? They are both 9" rear ends.

[fordman]

you will have to move the spring perches.

[westco]

I was about to post the same question I can get a 9" out of a 75 for my 69....up to what years will bolt up to my 69

[fordman]

up to 72 without mods.

[grabberblue72]

I have a dent side diff in my 72. I had to weld new perches on. The diff is wider then a 72 diff. The extra width is nice with 8 inch wide wheels. But 10 inch wide wheels stick out and the wheels rub on fenders. You also have to get a new u joint that will adapt your old driveshaft to the wider yoke on the dent diff. It is a pretty simple swap if you can weld.
the u joint wasn't hard to get either.

[cole71]

I know this is a pretty old thread, but I'm interested in the rear end swap you did Bahamablue? You just cut off the pad that the leaves set on and moved them where they need to align and weld them in? Also where did you find the u joint you talked about? Finally, is there any thing else you had to do to make the swap?

Thanks, Cole

[cole71]

Sorry meant grabberblue72. haha

[72BahamaBlue]

"I know this is a pretty old thread, but I'm interested in the rear end swap you did Bahamablue?"
"Sorry meant grabberblue72. haha"



I'm also considering a rearend swap from my '76 onto my newly aquired '71!
The front and rear springs on the '71 F100 are pretty weak and way too squishy for my liking. I just might change it all.

[FORDification]

Keep in mind that the pigtail on the bottom of the dentside front springs are a little larger than those of the bumpside. That means it won't fit snugly on the bumpside spring cup under it, it'll wander around a bit. Obviously not a good thing. And the dentside spring cup won't sit right on the bumpside's forged steel radius arms, since they're made to fit the flattened end of the dentside-era radius arms.

Therefore, if you swap in the dentside-era front springs, you'll also need to use the matching radius arms and spring cups.

...and in most cases, the dentside rear springs are wider than the bumpsides, which means you'd also have to use the matching frame mounting brackets and hangers.

[72BahamaBlue]

"..and in most cases, the dentside rear springs are wider than the bumpsides, which means you'd also have to use the matching frame mounting brackets and hangers."

I measured 2 1/4" wide leaf springs on the '71 F100, and 2 1/2" wide on the '76 F150. Definitely must use the matching hangers.
4 rivets each x 4 per truck x 2 trucks = 32 rivets to remove. Ouch.
The difference of 2 1/4" vs. 2 1/2" wide leafs would need to be addressed at the axle tube mounts as well.
I think adding a leaf to each side would be much more acceptable!

[cole71]

Could you not cut off the spring pads from a bump rear end and replace on the dent side rear end? ?

[FORDification]

That's what you'd HAVE to do....though I'd replace the mounting pads with new ones, rather than trying to cut a set off one housing and weld them onto another. You'd probably end up spending nearly as much money on gas for the cutter than you would just replacing them with new.

http://www.speedwaymotors.com/speedway- ... e,632.html
http://www.smileysracing.com/shopping/p ... 863&c=1552
http://performanceparts.com/part/Moroso/85090

[cole71]

I see now. I guess I just read that wrong at first. Is there any where that sells the pads new? I've never looked for them before.

[FORDification]

Did you click on the links I posted?

[cole71]

thanks, haha