well, i know mine did the same thing,and a few people here told me what im telling you,i was ready to tell them to go to hell,but they were right.
try cutting open the oil filter and see if theres metal particles in there.If you bought a rebuilt SB or had it done,i really doubt they put it all together and break it in for you then tear it apart to give to you.
It could easily be a lifter. Are these hydraulic lifters? There is special lube that is supposed to be installed on the lobes of the cam to ensure proper lubrication on first start up. The motor will run hot, depending on alot of things.. Especially if its just sitting there idling. Guys remember technology wasnt was good back 40 years ago than it is now! Most classics will run hot if you let them idle, unless you take run no thermostat . Anyways, are you sure the valves were adjusted correctly? If they are hydraulic lifters, how did you adjust them?
we did the old loosen em till they click then tighten 1/2 turn I think. Im really starting to get worried about this cam, I am gonna pull the pan and Look for shavings in the filter
figured it out Turns out this little tin tab that was on my old block that we put on the new engine was rubbing against the harmonic balancer Which caused countless hours of cursing/thinking. Thank god I didnt have to pull the motor or anything. Thanks for all the responses. Got her running good, broke in the cam. She sounds real nice with the new cam, more like a muscle car So excited later guys Im gonna go down a cold one This tin tab we thought was some form of timing mark so we just threw it on