Mr cox it is NOT a problem, conversions are from glow (check to Davis Diesel site) Even ringed engines work well my ST 40 has a davis head and it light s right off with an electric starter
it will not hand flip start due to leakage past the ring on hand start with a fast spin with a starter it lights right off . my OS 1.08 conversion has very little issue and flip starts
The "cream of the crop" are my irvine MRKllls Davis heads they are true ABC and as glow they had great compression martin