I have a 89 cadillac eldorado with the 4.5 lit that as i was replaceing head gasket and giving everything the once over i noticed that coolant was leaking past the 1 and 3 cylinders where the cylinder meets the block, i noticed it from underneath looking from where oil pan mounts. i researched that the cylinders are removable and has a rubber o-ring .i managed to pull both cylinders and I'm worried about getting them to seal properly and about finding replacement gaskets. i found them in a kit but i dont need any other gaskets i already purchased kit. i was wondering if there was and sealants or epoxys that i could use to seal them permanently or if anyone knows exact dimensions of replacement gasket. diameter mm width mm even weight

thx
a life long caddy enthusiast