A callout to mopar 340 folks. I'm looking to start from a scratch build for a 1969 casting. Would anyone have information on how the timing cover markings changed from the passenger-side, and then later to the driver side of the engine on the final production of the 340's? What year did this change occur and how did they make it happen, was it a change in the key-way in the crankshaft for the harmonic balancer? Would it make sense to search for a passenger-side marking cover? Thanks for any input!
The 1964-1968 273, 1967-1968 318LA, and 1968 340 were equipped with the separate tab on the passenger side with matching damper, or harmonic balancer, for the driver hose inlet cast iron water pump. The following images show the timing cover for the 1964-1968 applications and the separate timing tab the separate bolt on tab:
1969 and some late 1968 LA engines including the 273, 318, and 340 have the timing "tab" cast into the cover housing on the passenger side, and a matching marked damper. The following image shows the 1969 and late 1968 cover:
The following image shows an installed 1969 340 timing mark setup:
The cast in timing "tab" was relocated to the driver side for 1970 with the new aluminum water pump with hose inlet on the passenger side along with matching damper with relocated marks. This cover was used through 1991 on the LA engines, although it was revised starting with the 1978 318 engines to allow the seal to be replaced without removing the cover.
The following image shows a 1970-1977 timing cover:
The following image shows a 1978-1991 timing cover:
The 1962-1966 (-1967 for Canadian models) 318 Poly engine has a similar cast aluminum cover with timing tab and matching damper as the 1964-1968 LA engines except it has an extra mounting hole on the driver side. It also uses the same water pump. The 1956-1961 Poly engines used a different cast iron cover.
