[ckhd]

I wouldn't think it would be bad to use poly body mounts in a street machine, but I notice your sig says "K10". When you're out 'wheelin, then you subject the pickup to a lot more flex than one that just cruises the streets and goes over a speed bump or two now and then.

Poly doesn't flex. When you have your frame flexed to it limits as you are driving over something while using four-wheel-drive, then poly may bend something. Rubber will give a little and help absorb some of the stress that you are subjecting the body to.

I would use poly in all suspension applications. In fact, I'm going to completely rebuild the suspension in the burb here in a few weeks, and I'm using poly anywhere I can find a poly part for.