Howdy all, I've removed the intake manifold from the 4.0 in preparation for the new fuel supply I ordered. Now I'm wondering if there's any maintenance I should be doing before it's reassembled. I'll definitely be cleaning the top of the engine while it's exposed, but do you guys recommend doing anything else while everything is more accessible? Is there any reason to mess with the fuel rails or injectors? Also, the seals on the manifold look ok, is there any reason to replace them? Thanks guys!
Davisdog

 

You need a new lower intake gasket, for sure
Use a bit of RTV(sealant) at the coolant passages on all 4 corners, both sides of gasket

Use lock-tite on the lower intake bolts, they only use 15ft/lb torque so tend to loosen up after a while and cause vacuum leaks

Use a 190-195degF thermostat with "jiggle valve", this valve goes at the 12:00 position, it lets out the air when refilling