Guitplayer, do you know the compression ratio of your 327? if it's a low output with 9.5:1 or lower, you can run 87 octane.

1957 Chevrolet 5700 LCF 283 SM420 2 speed rear, 1955 IH 300U T/A, 1978 Corvette 350 auto, 1978 Yamaha DT175, 1999 Harley Davidson Softail Fat Boy