SB Timing Cover interchange???

upto 1969 the dont have the timing cast into them. After that upto 1992(318) or 1993(360) they are all the same.

'69 was the first year to get the timing marks cast into them and they were cast on the passenger's side. Starting in '70 they were cast on the drivers side. The '68 and back has a bolt on timing mark bracket. This makes the '69 a one year only cover.