I was removing the intake piping to access the exhaust pipe on my 603.970 engine. What filth!!! A severe coating of gunk beginning at the egr port. I've a mind to remove the intake manifold from the head and clean it too. The stuff must be 1/8" thick. At least its soft so I don't think any passed throught hte engine yet!
I beleive I will blank off the egr port instaed of just blocking the vacuum tube that operates it.
1991 350 SDL