From memory most VL are 15/16" bore in the master cylinder VE had a larger piston in master cylinder and it was a progressive rate to get the 2 pistons out to the disc quicker, I have found some Subaru WRX and Forester came with a 1 1/16'' master
that can be adapted to your VL booster which gives a nice pedal feel and gets the twin pistons out to the disc with out to much pedal travel after all you don't want your pedal hitting the floor just as the brakes start working because of incorrect volume efficiency .....FC427....