AEIO-360 vs XIO-360

I know the AEIO has a solid crank and the engine weighs 331 lbs. Whereas the IO does NOT have a solid crank and the engine weighs 300 lbs.

The IO-360 can accept a constant speed prop, whereas the AEIO cannot fit a constant speed prop (no oil flow through the crank).

Anyone know what other differences are there between the two motors?

I do not believe that the AEIO engine has a solid crank. The AEIO prop flange does not have the lightening holes like the standard crank has. My AEIO 360 with aconstant speed prop works very well.

you need the complete model designation to make comparisons. Including the suffix's. Most aeio's were constant speed capable. Older aeio had crank shafts with a thinner flange that may have lightning holes in the flange. Later versions had a solid flange without the lightning holes. Maybe that is what you are calling a solid crank?? The difference in weight between the solid crank flange crankshaft and the lighting hole crankshaft version would not be anywhere near 18 lbs. when considering the shaft only. that is assuming they were either both counterweighted or not when doing the comparison. you have to compare apples to apples. my guess in your example, one was counterweighted and the other wasn't.
The weights listed by Lycoming and others for each model even with similar crankshafts, is very misleading as accessory type has a lot to do with it..ie. light weight starter vs. older style heavyweight, alternator supplied by Lycoming or not. mag style..Bendix 1200 series have considerably more weight than slick. etc. so the basic engine may be very similar and its the external components that make a difference.
Happy New year,
Mahlon