I swapped from a set of fully ported Roush 200 Iron heads to the 215cc iron Cylclone heads on my 393 in my fairlane. so far it has picked up in the 1/8 4 tenths on motor and 5 tenths on the juice. I would say they are a helluva set of heads, and cheap too!

I have seen several sets of them for dirt oval cars, some of the earlier ones came with pushrod sleeves in them making a nice straight shot, the ones I got had none and were a little rough looking on the casting of the intake port, but none the less, my heads flowed almost exaclty like the others with the pushrod holes sleeved. Mine flowed right at 312 cfm at .650 lift right outta the box. However, they jumped to around 338 after porting. Also, I think I gave around $860 bucks for them from flatlander assembled with doulble springs.