they also say the 4000Q rad is a bit bigger and a bolt in (Can anybody confirm this?). <snip> I'm runnin a 4KQ rad in the ur-q and also a 4KQ A/C condensor. I don't think the 4KQ rad is any bigger Vs the ur-q rad though. Both fit & work great. You kin even trash that funky rad hose for the aux rad with this setup! -glen