With arp rod bolts and proper compression your block is done. Dont upgrade the crank because you think it will break. Think of all the stuff you habe seen foolish ppl do to there cars and how many cranks have actually broken.
The sbc will take a hell of a lot of abuse. Dont spend it if you dont need to. Best to leave it stock unless your going to upgrade the entire rotating assembly. You cant just toss in a steel crank the entire rotating assebly will need to be rebalanced. Also rods fail before the crank will let go. If not going 383 let the machine shop return it to spec.
Also did you clean the head gaskets before you checked the deck height. Usally a block is decked in round numbers. .010 .015