I have a 426-2 and a 426-3 manifold but never did any dyno comparisons between them. I opted to go with my dual Indy Dominator tunnel ram instead just because Hemi's are supposed to have dual carbs. Looking back on it now I wish I would have dyno'd it with all 3 manifolds. Undoubtedly, the tunnel ram is making more power though.

1963 Belvedere 440 Max Wedge Tribute
1970 Charger R/T S.E. 440 Six Pack
1970 Challenger R/T, 528 Hemi
1970 Charger 500 S.E. 440 4 BBL
1970 Plymouth Road Runner 383
1974 Chrysler New Yorker 440
1996 2500 RAM 488 V-10 4X4
2004 3500 Dually Cummins 4x4
2012 Challenger R/T Classic.