I had a compression test done today and the right side was all 135

The left, ends were 135 each but the middle 2 95.

Mechanic thinks it's the head gasket but that's a $2,200 job.

Any thoughts appreciated. Engine seems to run well, doesn't smoke and seems good once warmed up a few minutes. I drove it 300 miles a day 2 days is a row, it really seemed to hum. During that long trip one morning there was a little white smoke at startup. That seems to have gone away. I use ethanol free 90 octane and just put some seafoam in the gas tank and a little in the carb and an ounce in the oil tank. When I start it in the morning there is no smoke but a little water coming from the tailpipe until it warms up.

Thoughts? Should I expect problems, any troublshooting to avoid them? Motor longevity?

Motor has 37k miles unless I was lied to. Seems like I wasn't though.

 

I can't imagine what would cost you 2200k for a pair of head gaskets.

 

I agree that you should fix the issue before it becomes a bigger problem. But that price seems kind of high for a USD (United States Dollar) amount.
Might not hurt to shop around a little bit...

 

Totally. Find a local mobile mechanic and he'll do it for 500 bucks, if that. Place is trying to gouge you; they saw ya comin'!