How To Install A New Rearend - Ford 8.8

Moore used this Lamb Components digital angle-finder to determine the 4.5-degree pinion up-angle.

Moore used this Lamb Components digital angle-finder to determine the 4.5-degree pinion up

Converting To Leaf Springs
Perhaps the biggest part of swapping the 8.8 into our '67 Mustang is converting the housing from coil springs to early-style leaf springs. The first step is to remove all the coil-spring brackets off the housing. Ray Currie gave us a tip that the axletubes on these Mustang housings are especially thin, so never use a torch because the heat will permanently warp the tubes. The approved approach is to use a cutoff wheel and smooth everything with an angle grinder.

Disassembling the Ford 8.8 to remove the old four-bolt axles and brakes was much easier with the help of our Ingersoll-Rand cordless 31/48-inch impact.

Disassembling the Ford 8.8 to remove the old four-bolt axles and brakes was much easier wi

Tim Moore recommends duplicating the position of the leaf-spring brackets to the pinion flange based on measurements from the stock '67 Mustang housing. Our new spring pads came from a small company called Ultimate Driveline; they were the only pads we found designed for the small Ford 211/42-inch tubes employed on the 8.8. We used a digital angle-finder to determine that the pinion angle was 4.5 degrees up with the leaf-spring brackets at 0 degrees or horizontal. Next, we measured the distance between the centerlines of the old leaf-spring brackets to get a figure of 4231/44 inches. Then we measured the overall width of our new housing from the outside edges of the housing flanges, which came out to 5411/48 inches. This produced a difference of 1131/48 (5411/48 - 4231/44 = 1131/48), which was then divided in half to come up with a spec of 5111/416 inches from the outside edge of the housing flange to the spring-pad centerlines. Once this was marked on the housing and the pads were positioned to create the proper pinion angle, Moore tacked each leaf-spring bracket in place on the housing and double-checked the positions of both brackets before welding.

Next, Moore determined that the spring pads needed to be 5111/416 inch inboard from the outer edge of the housing flanges to center the 8.8 housing in the car.

Next, Moore determined that the spring pads needed to be 5111/416 inch inboard from the ou

One point worth mentioning with rearend swaps like this is a dimension called pinion offset. This spec references the lateral position of the pinion gear centerline relative to the exact true centerline of the housing. All rearend housings have a pinion-offset dimension, with each housing offering a different placement based on its design. The difference in pinion offset from the stock 711/42-inch housing and the new 8.8 Ford places the pinion slightly more toward the passenger side by 11/44 inch, but according to our sources this should not present driveline vibration issues.

By Jeff Smith

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