Have anyone an explanation? I took off a pair of old 906 heads from a running 383 and found this. Looks almost like someone has made threads in the valve guides, in all the exhaust, not intake...

7667321-906guide.JPG (218 downloads)

70 W100 Power Wagon. 318 4-spd
70 Sport Fury 440 2dr HT
71 Duster 340
71 Charger Super Bee - 383/727
72 Charger "Sabotage" - 440/727 - Street/Strip
78 Warlock in beautiful patina