Andy-
I have a 4.2 L I am getting ready to install to replace a 215, maybe
this weekend. You should have no difference in valve gear, & I doubt
that the compression will change, unless you use the thin head gaskets
in place of the thicker 4.2 L later items. The stock 4.2 L is 8:
something, just under 9:1, the thin head gaskets make it just over 9:1.
The plugs are the same, timing is the same, no change in air cleaner,
or anything else I know of. Can't speak to a piston or rod change, as my
short block was assembled when I got it.
A different cam is definitely in order, along with new lifters. I
suggest the Wedge Shop, Woody Cooper, or TSI, Ted Shumacher (sorry if I
butchered your name, Ted), for cam specs, distributer curve info. You
are using a K & N air filter, aren't you?
If you don't have those e-mail addresses, let me know.
Jim Stuart
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