Any thing that puts the crankcase in a low vacume condition is king for ring seal reguardless of ring package. I would at the minimum, use a headder vent to each collector with the check valves at the exhaust nipple. NEVER go without a vent. try to get both valve covers sealed up and one scavenger vent per side per collector is the least expensive way I know of to do this. Other wise a vacume pump possibly electric for small engines or mechanical for larger racing engines is worth power in any engine. How much just depends. I hope this helps.