Piston rings where can I buy these

[King-of-kings]

got a 1963 3hp 3302S lightwin Evinrude. Top cyl has 80psi bottom cyc has 72psi. I think these numbers are a bit low. My 70 Johnson 1-1/2HP has 90psi. Ironically I think they both use the same piston and rings. Question where can I buy a set of stock rings for this old motor? Found one set on line for $75! any other options to get them cheaper? Part 378412 or 778419 or 203152

 

[racerone]

At 70 PSI you do not need new piston rings.

 

[F_R]

Comparing a 3hp with a 1-1/2hp is like comparing apples and oranges. Factors affecting compression pressures might include piston stroke and volume of the combustion chamber when piston is at TDC. Now that I've opened that can of worms, I don't know the answer

 

[racerone]

Same piston and same stroke.----Possibly a different cylinder head design.