Patch panel issues

[STOCKISH]

Quick question guys, i have done alot of rust repair on these trucks and have had the same issue every time. The lower B pillar patch has always been about 1/4-1/2 inch too narrow. When fit against the inner rocker panel the patch doesnt even come close to fitting properly to the cab corner. Each time I have had to cut the panel in half top to bottom and add 1/4 inch of material to it to make it fit. Is there maybe a chance the blazer and c10 door pillar patches are different and Im getting wrong parts or what. For once I would love to have door pillar patches that fit. Help please.