best xflow head

[lyonsy]

hey
jsut woudnering what is the best xflow head ive been told that the 86efi has best chambers but 87 efi has best flow.
now what are the modle designation of these heads ie c1 c2 d e1 e2 f etc.
also how poor flowing are the cast heads beside an alloy stock and is it true you can get more flow out of a modded cast rather then a modded alloy.
are there any difference between the leaded and unleaded heads in alloy.
mark

 

[Anonymous]

Probably do get more flow out of a moded cast crossflow as they will take lots lots of hogging out and they are already substantually bigger in inlet than Alloy crossflow but a lot of this is wasted gain unless you looking at staying the higher side of 5500 rpm most of the time (simple fact is most dont)
Considering this the alloy crossflow is then far superior in every other way as far as efficiency and performance goes (lots of old posts on this). Early carb alloyhead with latter size efi bigger valves allegedly flow best of all.