Thanks Cab. Any advice on piston choice is appreciated. The pistons mentioned are TRW #2355 .030 forged pistons. As heavy as they are I would think they should work but have not measured the thickness of the top. I also have on the shelf a set of KB 237 flat tops that are .040 over with very similar compression height.. I know the KB's could run a tighter clearance but don't know if they would stand up-especially with the top ring so high. The TRW's are old and would swell and require a lot of clearance.

What rings would you chose for this application?


Aren't there some 440 industrial motors that have the same type water pump and heads? Are the heads the same configuration as the 413-3 with a closed chamber and sodium valves?