need dimension on RV4????

Hi, guys. Can anyone give me the exact dimension from the front edge of the main spar to the face of the firewall(engine side) as measured along the side of the fuselage on an RV4??? I'm doing some computer comparisons on the 4 verses 6 model. Thanks for any info. Tom in Ga.

My completed fuselage measures 28 - 7/16 inches on both sides.