I have bushings for MSD distributors that limit advance to 10 and 14 degrees. I doubt you'd need a 14. IQ hit it, probably going to want at least high 20's for initial. If it starts OK locked out, why bother with any curve using a cam that large.
It was locked because the MSD distributor isn't designed for a cam that big. That cam will want 28-30 degrees at idle and the best bushing that MSD offers is an 18 degree bushing so that you must have only 20 degrees at idle to keep no more that 38 degrees total. Best to leave it locked or get a good distributor like the FireCore50. Or leave it locked and get a programmable ignition.