Poly IRS cage bushings? And front subframe bushings?
 

These might have been out for a while but this is the first time I remember noticing them. This site says they have poly IRS cage bushings and poly front subframe bushings... not sure if that's the front or rear mounts. Does anyone have any experience with these mounts?

Rear cradle mounts:
v12s Polyurethane Jaguar XJS

Front cradle mounts:
v12s Polyurethane Jaguar XJS

Page with all bushings:
v12s Polyurethane Jaguar XJS

I know this is advertised for the XJS but it will work with the XJ sedans as well.

Hi
I found them by an Facebook ad and did a read up. They do provided full kits for both. I think it is great value and will be looking into when I can afford it. They also have full replacement bulb kits in LED

The poly busing are stiff. If you put them all in you will have a totally different car that will be very direct, ride very harsh and be a bit more noisy. Fine if that's what you want. I put poly bushings in select places, the rack bushings, upper control arms, and the small rear trailing arm bushes. I replaced everything else with stock rubber. which offers good isolation. I know you are building a 6.7 LS1. That engine is going to overwhelm the rear as my lesser 6.6 sbc did. If you increase your rear traction you will get cage twist and axle tramp. I ripped up one set of the small trailing arm bushings and a set of stock cage mounts, they separated where the rubber is bonded to the metal. I'm not sure poly bushings would control the twist as is seems like the mounts are too close together to properly oppose the twisting force so. When I went to 235 series 17 inch tires on the rear I got axle tramp, then when it hooked and I didn't get tramp I got twist, which was so bad the drive shaft was hitting the body like a drum. I fashioned up a lower cage mount which is isolated on the body side with stock small trailing arm bushings. No more twist or tramp and no additional harshness.

Thanks for the responses!

How are those poly small-end bushings holding up for you? Did you get the softer (red?) or harder (black?) compound?

Speaking of those small-end bushings, I tighten them down when the car is back on the ground and suspension is at ride height. Is that the correct way to do it?
I don't drive the car that hard and I've already worn out a third small-end bushing on the right side.

I've been planning on making an IRS support similar to the one you have on your car before I get serious with the engine! I haven't decided if I want to use rubber or poly, or have bushings at one end or both ends.

Black, I dont think it matters how you tighten because unlike the OEM the center spins freely.

Search for lickahotskillet, his garage photos show another idea. I took his idea and reversed it and made it a bolt in just to test it. I was surprised how well it worked so I left it.
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Interesting I would be considering it for life span. But don't want to compromise ride to much.