Jag rears look as good as Mustang II fronts. Or should that be as bad. Might as well put in some shag carpet and dingleballs while you’re at it. It’s your car and you can mess it up all you like but to my eyes the guy who built it used the less is more principle, something not everyone has the willpower to do.
The XJS will fit without any narrowing. The rear fenders are 2" wider that stock so the IRS won't be an issue.
despite what is said here, the only way you can mess up your car, is to let somebody else tell you what they think it should look like.
A few things you need to be aware of if using the Jag rear... and as a side note, I'd do it. Jags have their issues, but their suspensions are first-rate. 1. Check the diameter of any shocks you want to substitute; the OEM ones are skinny to clear the axles. They're actually very good shocks, the only downside is a lack of ride height adjustment. 2. Changing the rear axle ratio won't be as easy as you think. You might have a Dana 44, but it's more likely a Salisbury (basically an English copy, but with little easy interchange with the US-built Dana), look for a drainplug; only the Dana rears had one. The 2.88 rears also used a unique differential/ring gear that won't accept any other gear set. It's possible to install 'regular' Dana guts in one, but you have to replace everything and use non-stock bearings and u-joint yoke. 3. Rear brakes. If you decide to convert to outboard brakes (and it's not a bad idea), you can get bolt-on donor parts from any XJ40 Jag sedan (https://en.m.wikipedia.org/wiki/Jaguar_XJ_(XJ40) ). You'll need the axles, hub uprights, and brakes. These are pretty easy to find used. As an alternative, you might want to look for a '92-96 XJS unit rather than do all the 'conversion' work on yours. These will already have the outboard brakes (the '94-96 used ventilated rotors) and most will have 3.55 rear gears as Jag started fitting OD transmissions. A few other details. The early '75-80 XJS used 3.03 or 3.31 ratios, that might use standard Dana gears but I haven't verified that. Three-series gears were also common in the XJ sedans, but those will lack the positraction found in the XJS. All of these use a Chevy 4.75"-on-5 wheel bolt pattern, but the hub diameter is larger, verify your wheels will fit.
The Jalopy Journal
