Looking For A Proven Cleaner

Clean them up, lap the valves, change the valve seals (may as well if you've got them apart) and swap out the stock valve springs for a better set. The Trick Flow TFS-2500100 spring kit seems like the most popular upgrade....especially if you plan to cam the engine a little anytime in the future. Or, just re-use the stock springs on your E7TE heads if you want to do it on the cheap.

Bolt them on and go. Your stock headers will even bolt right up to them.