327`s are great, just very difficult to find in a large journal size. The small journal 327 was made from 62 to 67, the large journal from 68 to 69.
So what many do is get a 350 block, a 307 crank and use 327 pistons.
If you put the exact same components in a 327 and a 350 with identical cars with the same transmission and gears and raced them the 350 would take it but not by much. Once again, you should not be concerned about horsepower. be concerned about torque.
Old Skool stuff. If you want to learn about max horsepower from a 327. Look up old articles about or by Bill "Grumpy" Jenkins. Back in the day he ran 331 Sbc (327+.030) . Was the man to beat!!
Unless your restoring a sixties car to originality go with a 350 for the reasons already mentioned. Having said that Chevrolet had some high hp 327's in the day. I think there was one version in the Corvette that was factory rated for 365hp. At that time the factory was under rating hp figures for insurance purposes.
Depending on which block you have, you could put in a 350 crank, 3.48" stroke. New aftermarket crankshafts / rotating assemblies are pretty inexpensive for a 350 and even cheaper used.
I have 2 327's I need to get rid of, one 66 short block disassembled and a extra small journal crank, and a 68 short block, and a set of double hump heads , and a old cast iron 4 brl intake that was on the 66 . sell em cheap, $150 for all.
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