JE pistons are $100 a hole. When I built my 4.125 bore 302 I had them do 10 so I had a couple spares. Maybe a bit pricey but the end result is usually worth the effort.
Open & closed chambered, The one experience I had in "79", my Cobra Jet in the Ranchero needed a rebuild. I had an open chamber 2v engine with a stock 4 barrel setup to run in the down time. Even with the timming way retared it would nock like hell unless you got into all 4 barrels. But that is an n/a aplacation.