Is there a down side to adding the power valve blow-out assembly to the 2300 center carb ???

Can't see any. It's just a check valve.

Thanks Mark.. I'm going to add the kit to a center carb as requested...I remember there was a discussion about the kit somehow changing the vacuum signal {in the 2300 series carb PV circuit} but it's been a while since I was involved in that thread and can't find it...Probably been longer than I'm thinking...The owner wants to add it as a safety measure...I told him if it's tuned correctly you would'nt need it...

Been doing 6pk carbs for 35 + years,have yet to find a blown power valve.Only bad ones were those that sat for years and dried up.