Originally Posted by
matthewpickup
my brother had a 2wd coscast head on and then took it off and put on a 4x4 (cant remember what it said on it but was not coscast) , however he took it
back off as he felt the car did not goes as well .
so is there a difference to coscast head to a non coscast head ?
4x4 head has smaller combustion chambers than a 2wd head.
Hence why if you use 4x4 pistons on a 2wd head you lower compression slightly to around 7.8:1