The OD of the GB journal should be at least slightly larger (e.g., .750") than the OD of the section forward to the muzzle (e.g., .740"). That way, a set screw low pro or a GI-type sight base can easily slide over the muzzle and still fit tightly on the journal.
Most barrel makers leave the GB journal long enough to accommodate both short lo pros and the longer GI style such as the YHM model the OP is using, other makers just assume only short GBs will be installed. Same with the distance from the gas port to the shoulder behind it, some barrels are drilled short for GBs used with FF handguards, some are drilled .020" longer to accommodate the front end cap required for clamp on type handguards like Magpul's.
Ideally, barrel makers are perfectly clear in their product descriptions so you know in advance if the barrel is going to properly fit your gas block and handguard. - CW