I’d agree with sail sfbay that asking others for the lengths of their cradle posts may not be the way to go. My cradle configuration and yours are probably not the same and so the necessary height of the uprights will not be the same either.
For me, I’d measure the cradle base and the location of the uprights relative to your hull and then figure out what kind of adjustments the cradle uprights would need to reach and support your hull. The draft of my 302 is 3’11” so I know the uprights will need to be at least 3’11” including pads to contact the hull. After that, extensions and screw adjuster pads are used to ‘fit’ the cradle to your hull.
I think most manufactured cradles (as opposed to DIY cradles) and their uprights are built to certain standard dimensions and then adapted with extensions and screw pad adjusters to get you to what your boat needs. For example, the ‘manufactured’ cradle for my O’Day 302 has 5 posts; 2 fore and 3 aft including one underneath just forward of where the prop shaft exits. The fixed uprights at the four corners are about 4 feet high. Each forward upright has a removable extension tube to extend the upright about 12 inches and all 5 posts have 14 inch or so adjustable screw supports on the pads. The rear screw pads add about 4-5 inches of reach. The forward pads add about 8 inches of reach to contact the hull. Oh, and my keel is sitting on top of about 4 inches of 2x10 boards on top of the frame to lift my hull high enough to make the uprights work (the lift is needed to make room for the pad under the hull).
Do the uprights/pads need to land on your bulkheads? I don’t think this is critical as your boat rests on the keel and the cradle uprights/ pads keeps it upright.
I hope I got your question right. I’d look at making a free cradle work. If it is close enough, you can spend some of your savings on necessary adjustments. Cheers!
