harmonic balancer help!

[seanrolandwood]

got a new balancer(6.75 summit brand) heated up in oven slipped over the crank end and gave it a few hits with my dead blow to ensure it was seated all the way....some say never do this(potentially damaging thrust bearing and so forth some say i do it all the time) but its done so here my issue the new balancer seams to be deeper on the crank end than the old (i didnt measure the distace before i pulled old one...awesome i know)did i just set it too deep on crank end and can i just back it off to where it needs to be or did i f&$# up and knock something out of the back of the block....what is the gap supposed to be at back of block between it and the crank....Please help any advice would be greatly appreciated thank you