the crower posted specs for mid lobe on the 403 (stage 3) grind is .472/.466 vs the ctr .449/.417
a few hundreths of an inch mean all the difference in the world of vavle lift.
when you slipped the timing belt, the cam was still wide open and the piston went SLAP!...but you already know that.

the problems that crower admitted to having with the vtec cams was that early grinds were too brittle and there are numerous people that ended up with 3-8 cams in the end. it is possible that the grind you got was stamped for the 403, but did not actually get machined...
and you would def have to have a/f and timing adjustments made (and most likely a shift of the crossover point) to see true gains...
and btw, you would not have a loping idle, the primary lobes do not see dramatic changes, unless you were running constant midlobe... there should be only a slight change in duration and lift on those lobes... at least i know they used to pump up the primaries a little.

anyway, sorry about your motor... sounds like you were on the way to some solid n/a power.