340 to 360 production transition

Agreed, a Magnum block is a better quality block with better lifter bores. If your going to run a Hyd. roller cam, stock lifters and the spider is just fine.

Like I said about bearing speed .... Yaaaawwwwnnnn...
I suppose if your racing heads up with deep pockets spending big on parts and heads and .... you know the drill... Otherwise, I would not worry a bit.