Those 3 inches of diff movement are your strength, remove the give and gain a bend! Same design team did the conrods! I have small dent in the floor pan from the diff hitting it.
In regards to the SURE products it is possible that the all the boxes have been ticked except the R&D on strength compaired to STD part. Quality doesn't mean much if its under engineered. I wouldn't expect to have an issue with the SURE engine mount as its quality is nothing short of beautiful! Alot of contrast between the 2 parts.
Either way, the savings in selecting the correct part once is key to a successful cost effective result.
Every man should have a V8 ute.....with a Chev badge.....and a Southern Cross sticker! Mods? What mods?