I see there are questions as to what "run" a Tomahawk block was made from. What is/are the difference in them between the runs?
There were a few minor changes made for the last run. I asked Mike the same question when I bought mine from the last run. I think that deepening one or two of the water pump bolt holes in the block so that Meziere water pumps can be used without changing the mounting bolts to shorter ones, as well as adding more block material so that a second set of straight oil pan bolts holes could be used for easier custom oil pan building are 2 things that come to mind.
Thanks to Jim W., it is one of the last of the first run. I had to shorten the cover bolts on the oil pump side was the only issue I had if you want to call it that. I thought it was no big deal.