Unported head quickness?

friends 71 Mustang Mach 1, me driving. 351C 2v heads 4bbl offy 360 intake, Holley 3310, Erson Hi-flow 2 cam, 1 5/8 blackjack headers and 2 foot glasspacks, 3.00 open 9 inch FMX trans stock convertor. 12 inch wide tires. 13.67 at 106. Dog off the line but picked up pretty good. His 4V heads were slower but could have used alot more gear. Never clocked my '68 340'd '65 Barracuda back then but I would regularly beat a stock 340 Duster in the 1/8 street race where neither of us wanted to go faster than about 70...and that was with a 7.25 SG rear, maybe 3.23 gears