Can somebody measure a quarter panel for me?

[OKGMC4]

I’d like the length from the door jamb to where the fender lip turns in on a 69-72 blazer. I started with a 69 long bed and cut 23 inches out of it, then made it a unibody. I keep getting rust above the doors in the roof from the inside out. I could cut the roof and replace it but seriously thinking about cutting the roof off permanently and doing a blazer roadster conversion. I’d like to know exactly how much more I need to shorten it. Hooking the door jamb and measuring to the fender lip down the body line I got 30 inches. What you guys come up with? Thanks in advance.