Ok... I believe (if i recall correctly) that you need to put a non hydrolic lifter in when measuring, insuring that you get the right length. after you have one in, you'll need to get a pushrod checking tool. Crane sells them. It's basically like a pushrod with ends that screw out. Once you have it in there and expanded to the longest it can be, you shoulkd be able to turn the pushrod with your hand with slight tention. Hope this helps! Look on Crane's site for more info!
66 coupe,V8 conversion, 87 302 roller motor, GT40 heads with 202 valves, Weiland Stealth Dual Plane Intake, mallory distributor, headers/ H pipes, C-4 tranny, Granada Disks, 8 in 3.80 posi rear, Magna performance suspension