86, block heater question ,,

[KansasIDI]

The early 6.9s had steel plugs there and they took a 1/4" square, like an extension, to remove them. Those were usually a BEAR to remove. The later 6.9s and the 7.3s had brass plugs that took a 9/16" socket to remove and were much easier to remove. I might be wrong and all of the 6.9s had the steel plugs, but I'm sure that all of the 7.3s had the brass ones.

My 86 had the brass plugs. So does the 85 I’m working on.

The 6.9 oil coolers have a coolant drain at the back, the 7.3 ones do not

 

[IDIBRONCO]

My 86 had the brass plugs. So does the 85 I’m working on.

So it must have been the A blocks that had the steel plugs.

The 6.9 oil coolers have a coolant drain at the back, the 7.3 ones do not

This is one that I most likely didn't pay enough attention to for it to sink in.