I did this a few years ago, first to a muncie 4 speed, then a couple years later to a tremac TKO 5 speed.
The muncie fits up in there just fine. Use the original crossmember. I had to shorten the driveshaft, just a bit, it almost fit.
Your 327-PG will have a straight bolt starter and small flexplate. You'll want to use a 10.5" clutch (10 spline disk to fit an early muncie) and a Nova bellhousing (they want a kings ransom for camaro bells, nova's are cheap and the same.)
Good luck and check back!
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