switching to Brad Penn, any flushing tips?
 

My '79 just rolled over 207k and she deserves the good stuff.
Short of cracking the cooler lines, has anybody had any luck with putting something in the old oil 100 miles before draining? Marvel's, etc? Would like to get as much crap out as possible. Will be pulling the sump screen for a look, too. Not changing weights, sticking with 20/50.
TIA.

You can always do 2 changes in a row!!!!

I wouldn't waste time dropping oil lines to remove old oil.

Best,

Doyle

Just change it while it's still hot to warm.
I like to undo the 2 clamps on the big "S" hose and drain the oil out of that too.

Only takes a minute and it's good to inspect that hose for surface dry rot cracks you can't see unless you flex it a little.

Some large aftermarket front valance oil coolers like the B&B have a drain plug too.