My XKR has worn out the inside of the front tires and sits much lower (14 1/2") than the 15 3/4" spec as measured from the center of the tire to the fender edge above it. I've already changed the strut mounts, know there isn't any camber adjustment and I'm thinking the coil springs are tired.
My 2001 convertible should use a JLM20706 spring but I can purchase a JLM21277 for much less. The JLM21277 is for the coupe which weighs about 100 lbs less in the front (1900 vs 2000 lbs). So if H & R offer a set of lowering springs for all the XK8 models, maybe the differences between the stock springs isn't a dealbeaker?

Does anyone know a reason not to install the JLM 21277 springs?

 

I am not sure why you think that there is no camber adjustment on the front tires. There is. It is the rear wheels that have NO camber adjustments. What you may mean to say is that you do not have SUFFICIENT camber adjustment because of the limited range of adjustments. I found that to be the case on one of my Jags when I tried to put-on more negative camber.

Springs usually do not collapse unless you have a zillion miles on them. I would probably welcome an XK with a front end that sits an inch lower, unless you have camber or suspension travel limit issues. As far as replacing the springs I would stay with the one specified for that model. When I last looked up the prices on factory springs for my XKR they were under $100 per side, which is really inexpensive.

 

May be a difference of models. This is the 06+ subsection, not the XK/XK8 one. Maybe the 01's didn't?

 

I reposted this problem in the older XK8 section, thanks for pointing out my error.