[fwayne]

Those smaller boosters aren't going to have the assistance of a larger diameter one all things being equal. But they should certainly help. I suspect you might have the wrong Mastercylinder to caliper ratio. a common size MC bore is 1" a 7/8" will give you more brake line pressure but require a bit more stroke. The calipers have a piston thats a certain diameter say 3" Its a simple physics of the ratio and that 1/8" at the MC makes a big difference.