My dad used to run a 427 with a 6-71 blower and a pair of 4 barrels, and if he remembers correctly, 1/4" line. He may have used 5/16", but never any bigger on any of his rides. I really doubt youd have any problems with 1/4" on a 216.

Jeff


My 1953 Chevrolet
1947.1 Gallery
1972 C-10 1/2 Ton & 1972 C-30 1 Ton