help w locating serial #'s to identify heads@ cam

[83Zombie]

short version. trickflow told me i could find a serial # between the middle 2 exhaust side ports and the valve cover rail. it was very gunked up and ive been trying to clean it out to see if i can see a # but no luck. everythings installed on a running car. it has trickflow valve covers and i was trying to see if they were in fact TF heads too.is it just not clean enough for me to see? and if they happen to be stock ford heads, will there be a serial # there too? also the car is cammed theres no doubt, but the kid i bought it from, also bought it that way, so again no clue, any easy way without complete removal to identify it ..thanks

 

[jsw81]

Do the heads look like they're aluminum or iron? Iron will look kinda rusty if that helps you any.