I bought a 39 with a 216 several years back, gassed it up, ran really good ..... for a short while. Then the pump went...gradually, had to chase the problem as it seemed intermittent. Rebuilt the pump and carb with compatible kits, been doing fine since.
The fabric reinforced diaphragm is pretty tough. But the little rubber pads in the check valves is what dramatically affects the pump when they get warped, cracked or otherwise deteriorated.
Those kits actually DID specify compatibility...... but, they came with a 1 year warranty. (wonder if they are cheaper by the dozen
)
Maybe the short warranty has to do with not having a clue what the scientific wingnuts might put in the gas tomorrow.
I'll post responses from some of these vendors .... if they come in.
Thanks