I have an 04 MCS with mild mods ( alta 15 % and 2% pulleys, alta air intake and a magnaflow exhaust.) I am looking to add more power and lately i've been looking to add a full JCW head conversion. Does anyone have any idea about how much more horse power i should expect after adding the JCW head?

 

JCW head? Don't bother. It's only slightly better than the MCS head, not worth the effort.

Either stay with what you have, or, IMHO, go with a true ported/polished head....

 

Not worth the money - go with an aftermarket head (eg Thumper performance heads) and you will see more alot more power

 

+1 on the Thumper head.

Kevin

 

Save your money and don't get the JCW head. We did alot of testing when we made our WMW head and the JCW is totally not worth the coin.