If it was me , I might forgo the purchase of another cylinder, and I only say that because I've run an absolutely hideous one before with very good results.
I got an ms441 from the scrap yard and got a big bore kit from farmertech and it looks terrible, like made by a 8 year old terrible! The spark plug hole and the decomp look like they were stabbed into the cylinder with an ice pick. The bottom of the ports were almost closed with casting flash and I had to grind about a 1/4 off the outside of the ports for it to fit on the case.
Anyway I got the bare minimum accomplished to get it on the saw and its quite powerful and regularly run a 28" full comp or 34" skip on it.
You just can never tell ? And I dont know how long it'll last me ,but for 18.00 $ its already paid for itself.