How much difference is there in performance between
a hf cast iron manifold and a custom log manifold ?

 

hf mani wont be able to keep ac, with a custom log it will flow better and wont crack if u can get one that has good quality

 

hf has better flow characteristics than a log imo

Beau

 

^^^^^^^^^^^^agreed

 

go log if you wanna kep the a/c.... but if you want to keep it ghetto get an hf and 1 crazy adapter plate

 

yeah as Beau said.. the hf mani is gonna flow better, exspecialy with a nice port job and good adapter plate. and its gonna run you less money. but if you are looking to keep ac, then a costum log would be in order.

 

My car has never had A/C except when the targa top is off

Sounds like a port matched hf manifold is the way to go