KMJ Performance Rockers???
My factory MP performance bushed 273 rocker arms hit my comp retainer as well....thats cause the performance springs/retainers for the sbm is usually a LARGER DIAMETER than the arms are designed for...lol
They almost all had a line grooved into them in the ''arm pit'', I also had to clearance the aluminum ones in the ''arm pit''
You are limited in retainer diameter...but you can get away with a LOWER int height on the springs and NOT have that problem.