90 90degrees bolt

there are actually 4 different bolts.The two mentioned are early bolts. there are two others that are alot better and increase oil fow and very strong The difference in these two is only the head. Besides these 4 there are others different lengths for the short adapters from later years. Something to remember is the later year blocks including the R3 and resto take a one piece gasket these are the same as a magnum block. You can squash the fat cork one in there but good luck with sealing it