John, I've got one under construction. Block on the engine stand, parts painted, head finished and ready to install, 261 Rochester B rebuilt and ready, and all the new stuff lined up and ready to go.
I found a short block literally partially buried in the Arizona desert. First thing I had to do was blow sand out of the cylinders because they were full to the top! It's a 1966 replacement block that had been bored .060 over. It was locked up hard because the cylinders had rusted badly and frozen the pistons into place. Couldn't break them free even with lots of advice from Hotrod Lincoln, so I tore down the bottom end then knocked the pistons out through the top with a 2x2 block of wood and a big hammer.
Everything on the bottom end was in great shape. Water never got into it. A very large lizard had crawled up inside through the open oil plug and mummified inside the oil pan. I have not idea how it ever fit inside! Made me jump when I dropped the pan and saw it. Darn thing was about a foot long and two inches fat at the belly.
The cylinders were pitted, so my local machinist tried boring the worst two .100 over to see if that would remove the pitting. (If anyone is interested, I confirmed that Egge has .100 pistons and rings available and in stock.) The boring removed the pitting, but the rings still showed slight shadows where they had frozen to the cylinder walls that could just barely be felt with a fingernail, so the machinist sleeved all six cylinders back to standard bore. Total cost for the sleeve job was $510 instead of $85 for a rebore.
There have been posts in the past in which others have expressed concern about boring a 261 beyond .060 due to the thinner cylinder walls. I have one that is bored .080 over, and when my machinist did the test boring mentioned above at .100 on the two cylinders, he had no concerns about whether or not there was enough metal left on the cylinder walls. I would have run the .100 pistons and rings if the old rings hadn't left scars on the walls. Sleeving the engine required boring all six cylinders out beyond .100 to accommodate the sleeves, and there was no problem doing that and fitting the sleeves.
Good luck with your project,
Matt
