LLFordman wrote:What were the wheels originally on? 1.5" each side sounds like an awful lot. The difference for a SVO/MarkVII axle is 1.5" wider in total as compared to a stock fox rear end.
My wheels came from a 1991 Saleen. Are you sure your info is correct? Part number searches suggest otherwise. Here is a summary of the info I have:
From Saleen Club Of America:-Fitment for 87-93 cars is very tricky, due to the brake system used. Non-Saleen front wheels tend to interfere with the center cap, while the Saleen rear was very wide and used high offset rear wheels.
-The 5-spoke was phased-in in 1989, and used thru 1991. The fronts are 16x7 with 4-3/8" backspace (10mm offset), while the rears have 5-3/4" backspacing (32mm offset).
From LMR, American Muscle, and an article on allfordmustangs.com on 87-93 wheels:1985-1993 Mustang GT: 15-16" diameters, 4"x108mm bolt pattern, 1/2"x20mm stud size, 63.4 center bore, 15-25mm (M) offset.So, if a stock 87-93 Fox Body has 29.25" axles and a stock wheel offset of +25mm (+0.98"), and a 87-93 Saleen has an offset of +32mm (+1.26"), then it would make sense that the Saleen axles would be 1.26" longer per side, which comes out to 30.51" Right on the money.
From foureyedpride.com: http://vb.foureyedpride.com/showthread. ... Rear-Axles-All 7.5 and 8.8 housings from 78 to 98 are the same width (this may or may not include the few 6.75s). They all also came with the same 28 spline pattern on the carriers. This means that any axle shaft can in theory be used in any housing assuming the correct brake hardware for the shaft is also used.
-The 8.8 axle was released in '83 and made its way into the fox platform in '86.
Factory Mustang and other fox body cars:
-Housing width is 59.25" with zero center section offset. Axle shaft length is 29.25"
-087-88 Turbo Coupe and 93 Cobra 8.8" axles are basically the same with 30" (3/4" longer) axle shafts meaning, they are 1.5" wider overall. brakes are 10" 4 lug vented rotors.
-87-92 Lincoln Mark VII 8.8 axles are 30.5" (1.25" longer) per side, meaning total width is 2.5" wider. brakes are 10.5" 5 lug vented rotors. SVO and 87-93 Saleen shared these axle shafts.
-99-04 SN95 housings are 3/4" longer per side, and the axles are 1.5" longer per side but they continue to share the 94-98 rear brakes.
-Fox axles are 29.16" long.
-1994-98 axles are 29.91" long.
-1999-2004 axles are 30.63" long.
-SVO/Lincoln axles are 30.41" long.
I have tried to verify this as thoroughly as possible looking at replacement parts from different sources including drivetrain.com, RockAuto, AutoZone, O'Reilly's, Summit Racing, Jegs, Lane Automotive, LMR and others. The information above seems to be spot on.
For example, From LMR:79-93 Mustangs - 29 3/16" long rear axle.
94-98 Mustangs - 29 31/32" long rear axle.
99-04 Mustangs - 30 11/16" long rear axle.
Stock Mark VII wheels were 15" in these years, so there is no reason they wouldn't fit behind my 16" wheels.
Thanks for making me put all this together in one place. I have now answered my own question. Now I just need to buy the parts.