Call Paul Forte, or any other good converter builder, and ask them I'm thinking a Mopar 11 inch core to start with and shoot for 3500 to 4200 RPM flash stall I had a custom built 10 inch Continental street and strip in my 512 low deck wedge pump gas stroker, that one went 10.30 at 128.+ MPH through the exhaust on Oregon pump gas with the air cleaner on in my 3450 lbs. street Duster I had Chris at Continental (310-674-1072) make me another street and strip converter for a customers 1968 Charger with a 484 C.I. crate type street Hemi pump gas motor in it, it was a 11 inch core that was rated at 3000 RPM stall and it works great The customer loves it also