Thanks for the insight. Yeah from what I've seen the poly seems to be an acceptable upgrade from the rubber for a street car. Just figured I would see if it would make a world of difference to upgrade now while I can.I did poly. Mine a street car. It was significantly cheaper to go poly and everything I read said it will be a big improvement over the rubber…not as good as delrin but good enough for me.
I just got my IRS back in after doing poly bushings, the delrin/aluminum rear diff bracket, MM tie rods, painted everything, etc…I have not driven my car yet so I can’t give real feedback on the poly but I’m sure it will be fine. Make sure your really clean out the bushing sleeves. They are not fun installing on the cradle.
As I mentioned above, I did put the aluminum rear bracket with delrin bushing on with a standard FRPP diff cover. It fits fine. Yes I should clearanced the diff cover but it did fit. It’s tight but I wasn’t buying another diff cover and I forgot to clearance it and I’m not dropping the irs again lol
Your mileage may vary.
I personally haven't experienced any wheel hop yet even with some tire spinning 2nd gear pulls and a couple small slides. So I'm guessing I should leave it as is.