The 848 head thats going on my 261 has alignment dowels on each end for the exhaust manifold. These dowels are eroded and rusted significantly. I plan to install dual fenton exhausts and need to remove these dowels and tap the head for standard bolts if necessary. Are these dowels screwed in or pressed in? What is the best way to remove them? Also, I have removed the rocker assy, springs and valves from this head for cleaning and inspection, expecting to find bronze valve guides. Can suitable valve guides be installed on these heads?
