There's an old trick that still works well on pistons with a little bit of extra skirt clearance- - - -knurl the skirts to tighten things up a little. I've added as much as .004"-.005" to skirt diameter at times. .002"-.003" is easy. We had to do that on a couple of the pistons in John's 261 when I helped do the buildup on it. Any machinist worthy of the name can do that operation with a lathe, or box 'em up and send them to me and I'll be glad to do it. If you include the connecting rods, I can also recondition the big ends so the rod bearings will fit correctly and have the proper "crush" when they're torqued into the rods.
Rather than hammering on the "full flow" oil gallery plug, you can probably use a big C clamp or a ball joint press to push the plug in, as long as the oil pan is removed. Drilling and tapping the plug about 3/8" to 1/2" deep with a 5/16" fine thread ought to give you plenty of bite to pull the plug back out if you ever decicde to go back to bypass filtering and eliminate the full flow filter. I've got a couple of 261's with the full flow capable in/out plug. I'm considering pulling that plug all the way out, threading the hole, and using a screw-in blockoff plug instead of the one that's hammered in and out for the full flow/bypass choice. An Allen set screw with some of the threads machined down smooth would work well, since all it has to do is block off a passage between the oil pump and the main oil gallery that runs from front to rear down the driver's side of the block.
Jerry
