Dumb hydraulic roller lifter question:
 

When dropping retro-fit roller lifters into the block, should the tie bar be toward the cylinder bank? It looks obviously like the neater fit, but I guess the tie bar could potentially rub the block where the casting is thicker in the valley.

No, the tie bar needs to be closer to the center of the engine. Make sure you measure for correct pushrod length. Stock length pushrods seldom are correct length for roller lifters and/or roller rockers