Question on the OMC 31.8 motors. Ive modded a few of these & always look for more performance. Ive heard the 82 year model was the best [at least of the older ones]. I finally get one to rebuild in a trade & find the sleeves loose. What got my attention is the head, there's many subtle & a few major differences in these motors over the years & hp's but this is the 1st of this type head Ive seen.





The difference is on the intake side of the head [3rd pic] & Im pretty sure it had the same deflector piston as usual. This looks to be padded there more than the other & is different at the plug too. Could this be why the '82 is said to be stronger? The timing spec for motors with this head would be of interest.