I think the cam plug on the back of the block is leaking i've pulled the motor twice and replaced rear main but still leaks. it looks like it could be coming from above and dripping on crank. there is no oil leaking from top of motor like rear intake or oil pressure sending unit. My question is what kind of sealer to use on the cam plug and can it be removed from rear without removing cam and knocking out from inside. I've built a few motors but always had the machine shop install the plugs.