Have to be careful about buying used ABC engines as well as iron piston with steel sleeves. Bought an OS .40FP from E-Bay, was good and a good price. Bought a K&B .20 Sportster from E-Bay, piston / cylinder sleeve was shot. Bought 2 Enya .15-III TV's from E-Bay, one piston / cylinder sleeve were shot, other marginal. I've had about a 2 out of 3 luck on used engines. Sometimes sellers will use weasel words to describe a bad engine, like, "turns smoothly" (i.e., no compression), "has compression" (but hides fact compression is very poor), etc. One extended lean run with overheating can ruin any engine.

Not saying not to go for it, but sometimes a bargain ends up costing more when you end up purchasing another engine for parts or purchase repair parts. Moral of the story: Buy new whenever possible, and used only from reputable sellers. If you befriend an RC club, might find someone selling an engine you can examine prior to purchasing.

Check your ARF's engine mount. Some come with adjustable. Others have various means of accommodating width including custom drilling & mounting of mount, check clearance. Then check required width of engine you intend to purchase. Depends on the engine, but differences between some .46's and .60's are close.

Regarding weight, I put a .46 ball bearing Schneurle engine in a used Great Planes .60 ARF, removed 6 ounces of lead weight in the tail. Replaced DuBro low bounce front tire with a lightweight, moved engine 1-1/4" toward rear of mount she now balances properly. It fit in the adjustable .60 mount. You may or may not have to add weight. I've heard that with similar planes like yours some have had to add a little nose weight, but You'll need to verify.