with some modifications, a 235/261 would fit where the 216 went inyour 48. I'm not sure about the 216 bellhousing/transmission and a 235/261.
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'50 Chevy Fleetline DeLuxe ('55 235)
'48 Chevy Fleetmaster coupe ('60 235)
Chicago
http://www.geocities.com/hellfish122