I'm needing to rebuild the bottom end of my 4.2L block and want to do it on a stand before pulling out my engine and transmission. The whole job will go quicker that way. But I want to start with a "slotted block". I've been in contact with a couple of sellers who have a 4.2L block, but none of us seems to know when the transition actually happened. We all agree that the serial number starts with 8L. But do not know the year and the serial number crossover point. Anyone have any knowledge of this?

Many thanks, Bill



Slotted Block