I thought your m/c was under the floor also. I had to extend the arm on mine to correct the problem.
You may just be able to drill a hole lower on your arm. Just make sure the push rod doesn't bind going thru the firewall.


1949 chev 3100 3 window. 350hp/327/m21 4 spd, 12 bolt rear, power brakes, 3" dropped axle from Sid's. Disc brakes next.