Hi GB.... Just have a used 356 cam to hand, so for what it's worth measuerd on unworn areas, sadly with a metric caliper.
Lobe lengths heel to toe 31.6mm, cam width at the base at right angles to a line through the lobe... 24.3mm
Bear in mind this cam has had some use, but looks to be relatively unworn.
The actual lift a cam gives depends on the difference between the distance of the heel and toe from the centre of rotation. When a cam is reground, to restore lift, material is removed from the back of the heel. In effect the starting point for lift has been moved nearer the centre of rotation. This is what restores the lift.
So if you have a reground cam, the heel/toe length will be smaller, but the overall lift should be back to standard.
With a reground cam, the followers now sit lower in the tappet guides when they are on the heel, and now they may be bottoming on the retaining grub screws and centre guide. Unlikely, but worth checking. We also assume the followers themselves are as they should be as regards
the distance between the contact face and the top of the follower locating slots.
Swarfy.