My Yukon is finally back on the road. My impressions on poly mounts are as follows...
I personally feel vibration when in D stopped at a light. I feel it through the brake pedal, the cab vibrates a bit, my bad side mirror shakes. We'll see what the wife says. Please note I set my idle high to deal with bad oem mounts and engine shaking. I'll put it back to stock. This might help considerably. I'm too tired to do it now.
Also note I have 160k miles on my engine with what appears to have been owned by someone that hates maintaining it.
When moving everything feels like stock. Like totally stock. I can hammer it and the engine stays in one place. No more headers hitting the body, O2 sensors hitting, or touching the starter wire. No more loud clunks. I had to tune IN more trans torque management on down shifts because I would get loud banging. Perhaps these mounts will mitigate that?
Do I recommend them? God yes. Many times over. GM has a serious ******* problem with their OEM fluid filled mounts. H3 mounts might work well too but when you have tight header clearances they might still allow hitting on the body. Please remember my Yukon has the 6.2, is tuned and will have a supercharger. I can't imagine H3 mounts lasting with large amounts of torque.
My overall recommendation is that if you replace your mounts, do headers while you're there. Even shorty headers. Or have bolts break like me and just do a long tube setup.
