it's been quite a few yrs since i messed with this. I used to put together a 470 bracket engine for some friends using stage 6 heads and a comp cams .690 roller. we used indy rockers at first and they were unreliable with the k1000 springs and ended up using harland sharps. the thing with stage 4,5 and 6 heads is the recommended offset intake rockers. we didn't use offset rockers but had to add push rod clearance at the bottom of the outside of the intake port wall. after doing this there were no more issues. don't do the crane offset intake rocker. i've tried that and the ones i have are very crummy. the fulcrum points are all over the place and they'll eat valve guides quickly.