Replacement vacuum advance can for 318 distributor

Standard vc-93 appears to be a readily available, viable option.

My current distributor is from a 318, currently it is on a smog 360 with cam, headers, eddy intake and carb. So 8.5 compression compared to the 318's 9.5.

The distributor specs are as follows:
Mechanical 25 crank degrees @2350 rpm.
Vac (original can) 12" vac = 12-18 crank degrees; 15" vac = 21-27 crank degrees. The arm says "10" on it though, so should only have 20 crank degrees total. Possibly the can on it now is not original?

I have been running 12 degrees initial timing.

The VC-93 specs are as follows: advance starts at 4.9" - 7", max is 11-15 crank degrees @ 13". So it has approximately half the total advance of the old can, and come in at a lot lower vacuum. Based on my limited knowledge of advance, this replacement can would actually be better suited to my warmed over 360 than the original can, right?