[HWYSTR455]

That is THE setup, sounds like they know what they're talking about. Using a mono-leaf perch with multi-leaf springs is the only way to go with high-power application, because it's the only way to positively locate (and keep located) the rear. I've seen cars that the track that have actually slipped the rear forward off the pads on a launch.

I my case, I had to use a longer spring pin, and slightly open the perch hole. I do run the lower insulator, but I could have probably gotten away with just a thin shim to take up the space.

If you're at the point of going through this, take whatever extra steps required to move away from using the upper isolator and positively locating the spring to perch. If you can, get rid of the T-bolts and use U-bolts in both locations too.


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[Tinindian6702]

What was the reason for using a longer spring pin and opening the perch hole???

[HWYSTR455]

So the pin passed through the perch hole completely. Once you look at it you'll see what I mean.