Guys,
Regarding boring 260's. Reference: Ford Motorsport 1987 Performance
Equipment Catalog, pg. 16. "Many 289-302 parts fit earlier 221-260 engines
(which had smaller bores). They also had less metal around the bores, so
you can't overbore to come up with a 289."
Also, on page 8, same reference. "Max. Bore Dia. 4.030 289/302 CID" We
can probably assume this same advice also holds for 221, 255, and 260
blocks. We all know people who have bored out bigger with no ill effects.
Others have not been so lucky. Boring a 260 out 0.200" seems beyond
extreme. There's also a rumor that in a garage somewhere in Grand Rapids
there's a light bulb that has been burning continuously for the past
fifty-eight years. It's a story we'd all like to believe, but for the other
billion or so light bulbs in the world, six months is about all we can expect.
According to my sources, early 260's had two freeze plugs, later 260's were
like 289's with three freeze plugs. All these Windsor blocks are "thin wall
castings" and they aren't kidding. You are probably well advised to have
the cylinder walls checked ultrasonically before even boring out 0.030", let
alone 0.200".
Bob
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