There is a product that Napa or 1 stop sells called the right stuff it is awesome and can dam near seal anything it dries just like rubber, better then RTV sealant. Good luck
89 YJ with: 2.5 OME, SOA, MX-6 shocks, 33" ProComp MTs, AE. 589 rims, SYE + CV driveshaft, Homemade Bumper and nutter bypass. Also looking for some 44s to put under it.