Joe,
First time I ever heard this. I will have to do some
research of my own to confirm this.
My understanding was that any block machined for 4-bolt
mains got the external oil cooling modifications as well.
Colvin certainly did a hell of a lot more research than any
of us did in this area. BTW, I did find the passage in his
books regarding this, but he didn't mention anyhthing about
the oil plumbing being different. I'd still have to contend
that 4-bolt enabled blocks would have been drilled for the
external oil cooling provision. Keep in mind that when the
machining process was being performed, there was no tie-in
to the application ( SHP vs. non-SHP ). All 4-bolt blocks
would have to be assumed to be SHP, so I expect they all got
the external oil cooling modifications. If, as you contend,
some 4-bolt main blocks were used in place of 2-bolt main blocks,
I still think they would have external oil cooling provisions.
Anybody else have an opinion on this?
Lastly, do any of you know if 4-bolt main truck or fleet
BBC engines did not have the external oil cooling provision?
Steve
Steve