Someone needs to start re-casting 340 blocks

Dan the man said
I googled this to be sure, no factory 340 blocks came with 4 bolt mains. The block did have thicker webbing if you wanted to go to 4 bolt mains. The aftermarket blocks are a 4 bolt main bearing block.

My understanding is that the meat was there in the "TA", but needed to be drilled for the extra bolts.