?!?! Can I use '68 pistons for a '62 rebore?

Morning Gents,

Working on a 1962 Evinrude M#35530 Lark 40hp.

Have a bad cylinder and need to rebore it.

The original oversize cylinder for that motor (#378697) is NOT AVAILABLE ANYWHERE IN THE WORLD that I have found, not on ebay, not anywhere.

The '68 piston is a little bit more available and there are a few out there. I was able to find an oversize piston (#383069) and OS rings (#380109).

The blocks are different part numbers but look identical. I called bombardier and they actually talked to me (you know how they don't like to talk to you unless you have a '98 or newer). They said c.i.d. was different but both years are listed at 43.9 cid in the book!

The '62 piston ring side clearance is 0.005-0.0065.
The '68 is 0.0045-0.007 (greater?).
The piston skirt clearance is the same (0.003-0.0045). Also endgap is the same (0.007-0.017).

The pistons look visually identical to each other and measure the same height but are differnet part numbers. The rod is a DIFFERENT part number as well, but the wrist pin is THE SAME (some light at the end of the tunnel). The underside is the same visually. The '68 piston also has a larger flat spot on top than the '62.

Can I use this '68 piston in the '62 motor? What about side clearance?

Thanks!

Shawn T
Wichita KS

Can't say he will have the original but then he maybe able to point you somewhere. http://www.ganotech.com/ IMHO: OMC parts from the 50's and 60's = this part number superseded by this part number superseded by this part number year after year. And difference could be as simple as it was painted a different color. Don't know that a few hundredths of thousands matters all that much on the old motors. Pretty much all of them will still be here long after the 2000 motors are dead.