alright here we go....I was looking for heads for my 99 and it boils down to fr500 vs the 03 cobra heads. Which one is the one? What do you think that i'll see from a head swap of this nature? What cams would I want to go with?
5.0's 4 ever said:The complete assembled head on a 03-04 mach 1 is the same as 03-04 cobra. I would just go with a set of 03-04s over the FR500s, you can pick them up for very cheap fully assembled. You could use them as is or spend the money do some porting and upgrade the valvetrain.
03SilverSnake said:Im not completely sure of this but the 03/04 Machs use 5.4 Navigator cams
They get their gains from two things. The dual runner intake which gives you two torque peaks(giving more area under the curve), and the valvetrain specifically is deisgned to run at higher rpms, where the stock ones can't handle much more than the stock redline. I'm sure they changed the valves and such as well, but I don't know much about them.What makes the FR500 valvetrain superior, specifically?