I just rebuilt an MS290. I used a Cross piston and cylinder kit and the Cross pop up piston. I was very impressed with the quality of the cylinder. I am also very happy with how it runs. You can use a 390 cylinder on your 310. Cross Performance Stihl 039, MS390 cylinder kit* Cross Performance Stihl 039, MS390* Pop-Up Piston Kit
If it’s a saw you’d like to make right, then go OEM or higher quality AM like what’s posted above. The cheap eBay kits are inconsistent... but fun if you’re into saws. They probably require a little work to make them last (port bevels, better rings, etc.). I’ve used a few Huztl kits and have rebuilt with oem.
Yep I agree ... we’re i to do any saw work for hire ... I would insist on oem or I simply wouldn’t take on the job ... the cheep price sounds good right now but down the road after the saw Grenades I wouldn’t want to be dodging the rocks that the customer is throwing at me !