OMC 2 cyl experts

[Alan Power]

Or anyone!
Lifted the powerhead of my 55 rude tonight, going to start playing with modifying these to try and learn something - Pretty dumb in this field!!!:(

The first thing I noticed was the exhaust passages in the powerhead don't match up with those in the mid. This is prob. a very dumb question but can I grind these out to match, If so how far should I go or is there any point at all?

Also while I have the p/h off are there any exhaust mods I can do in the mid, redirecting water etc. :confused:

Anyone with any info on modifying these engines I would love to hear it.

Alan...

[novalves]

What year is it?

Model# will make it easy for transition years.
These twins evolved with many design changes

[Alan Power]

Mod; 55903S, it's a 1979 55Hp. I also have a 1971 model that I bought for it's LU what parts can I use from this, I know the electrics wont swap but I have also heard that the '79 motor has lighter con rods and they are not too great can I swap these for the '71 rods?

Alan...