I Need to change out the stock Motor mounts on My C5 I just hit 80k on it and Im sure there the originals but either way they are shot from the extra abuse my 500hp camed motor has been torquing on them. I was looking at the Pfadt mounts but there Kind of pricey and also a fairly new company Hinsen has some poly mounts out there are saposed to be more gentle on vibration, I dont care to much about that its my race car I want it to feel as mean as it looks and sounds and I dont want to feel the slop in my drive train through the shifter and in my sotp meeter anymore 
I will be putting in a new 3.90 geared diff soon too but I am looking for feedback from any of the LS motor guys that have run upgraded motor mounts and what they thought about the Vibrations? I am looking at these right now for the solid option.
I’d put poly mounts in it, they are very stiff
Eh I wouldn’t do solids just go poly
I did it on my Camaro it was a mistake and it also made its a POS to drop the tranny
Yea I can get the pfadt poly mounts for $207 brand new with a coupon I have right now on ebay? I was looking at the diff mount they have too but I dont see why you would need that with upgraded motor mounts because that is where all the twisting is generated from is at the motor and then transferred through the drive line so I would think if the motor doesn’t move than nothing else will either since the Vette has a torque tube connecting the motor to the trans and diff all the torque is then transferred back to the motor. Up and down movement under heavy load will still occur from the irs bouncing but I don’t run my car at the track or launch it hard, I just want some good motor mounts to stiffen things up a bit and get rid of the engine and drive train rocking
Looks like the Hinson Poly mounts are the best option right now for the price