It will quickly destroy the main bearings also! I would strongly recommend pulling the pan and physically checking everything to be sure! I once had a 67' 273 four barrel engine that I bought cheap. I soon found out why, it vibrated but only at 3K plus RPM! I pulled the pan and found a sleeve in #2 cylinder and a 340 rod installed in that location. Lmao! I changed the rod and all was well. For some reason that particular 273 was very powerful compared to others I have had.
