Brake booster for drum vs disc.

[oldcarnut]

I ended up with a booster for drums instead of front disc.  According to the supplier it doesn't make any difference.  Anyone have anything to counter that?  It don't feel quite right but before I try to make adjustments to mst cyl rod lengths or whatever, do I need to have the other type to work right?  This is the second time Advance gave me a different (one size fits all) rebuilt booster or the 70 RR w/disc.  First one didn't fit the plate.  If I take it back again I'm going to just go for the refund and get the one folks here say is at NAPA but I want to know for sure.  Do both styles work for either setup?  Thanks