As far as motor mounts lifts... I'm running Daystar and as far as vibrations are concerned... they've worked themselves out..
The Daystar were made for M.O.R.E. back in the day. But M.O.R.E.'s rubber 'bulletproof' one's were the next better after I got mine.
So there were for a 4.0L, and the mechanic I had working for me installed them for me. He used like a million washers on one side of them to make them work. I'm not sure what the issue was compared to my 2.5L... And why a shorter bolt wasn't the answer... All I know it that they've been in there for a few years and I've never had a problem.
Problem I had was really at idle but now that I'm getting used to the OEM, it was while moving also. The dash would vibrate just enough. If you have stock seats or stock type seats, these absorb much of the vibrations also. Run a suspension seat and you'll feel everything. You can see the problems with running a 4.0L mount set in a 2.5L if you check out the JKS/Currie install. I talk about the differences between OEM and poly in the JKS Budget spacers review.
I can really tell at lauch the engine rolls a lot more and it feels a bit slugish off the line. After running the OEM's I alsmost think the engine has died when I'm stopped. Long trips, (+500mile) were a bit of a bear. The vibrations would really beat you up. I do a lot of 300-500mile trips so it was a bit more important. Not to mention, for some reason the vibrations from the engine were being transmitted directly to the exhaust and breaking hangers off left and right. I've got the exhaust set up a bit differently but it should absorb the vibrations enough to stop it form happening. Weird side effect that may have been caused by the sum of the engine mods.
Oh and there's the roof rack. It would rattle violently at idle when empty. Drove me crazy. It was like having a monkey on the roof!
