Anyone know if the steering arms off of my drum spindles will fit my front steer 72 chevelle disc brake spindles looks like the caliper is going to be in the way.Also I took the proportioning block off of the same 72 chevelle,Does it have the holdback valve built in? Thanks in advance krangar

yes they'll work but the lh stuff off the chevelle needs to be put on the rh side and vice versa.
you'll need a disc brake m/c and if it were me, i'd go ahead and use the splitter valve and see what happens, it may like your wheel/tire combo....