BB, $250 is a steal. I know they have alloy bores but still, domestic use should see a whole heap of use from that.
It may have even been a post by you on here that really cemented the idea of a new motor. I had to chemically weld the 1 quart fuel tank on the Briggs. Try as I might, I couldn't find a proper replacement tank with support strut. That, and like the proverbial cat, the amount of movement it had when I was test running it on a piece of cardboard at just above idle...I shut it off in case I cracked the case. So she's been overhauled and is sitting happily on a shelf in the storeroom. Not sure what will become of it, but that's a problem of choice for a later date.
So here are some pretty well final pics after the engine change. Just waiting for a replacement metal handlebar badge really. If anyone is thinking of the GX100, it bolts right on as it is available with a 5/8 shaft at the correct height. You will need some new bolts to hold it to the deck, the ones for the original Briggs are a bit too long. No more than a few dollars.
Here is hoping to another 50 years of service.
I don't collect mowers. I just require Multiple Mowing Solutions™.