thinking of buying crane gold 1.6 self aligning rrs for my 93z. anybody on here use them? how are they. what else would I need as far as retainers and locks go. also what springs are good with these?could I pick up 15 hp with these.if you know part numbers let me know.may eventually add a cc306 cam down the line. I want a stronger valvetrain than just a basic hotcam setup. thanks