Wayne,
You're not that young are you? "Punched out" is an old hot rod term for overbored (larger P/C).
Shuie,
The most common method to find out is to remove the cylinder head and measure the cylinder bore. A more involved process would be to tip the engine on it's side and measure the volume of the cylinder + combustion chamber (w/piston at BDC) using liquid from a measured burette through the spark plug hole. You may have to do some research on chamber volumes and do some calcs and extrapolating to arrive at a best guess of your engine displacement.
However, before you get too far into dismantling the engine, hook up a battery to the starter and perform a compression test (even a leak down test). From this, you'll have an idea of the integrity of the engine. "Smoking" could indicate worn valve guides or valve guide seals, tired oil rings, or merely an overfilled oil tank or a leaking valve cover gasket.
To determine what camshafts you have, use a dial indicator and magnetic stand (can be purchased inexpensively). Remove a valve cover and measure the valve lift at the rocker tip and compare with published cam specs (do a search here). A degree wheel attached to the flywheel or crank pulley will give you a more accurate picture of valve opening/closing specs.
My apologies if you have no idea what I'm talking about. If so, find someone with the tech background to assist. You may have to pay a shop to perform this exploration.
Sherwood Lee
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