In put on 351 Windsor motors

[Lynn]

OK, I'll take a stab. Biggest factor is whether the engine has had "proper care" for the first 85,000 miles. If not, then maybe 85,500????
Lookig at the pics, one would guess that the PO took very good care of the engine. Regular oil changes are the most important. I remember an inordinant number of these engines sludging up horribly back in the 80's (I owned an independent repair shop at the time). More than one full size Ford or Lincoln had to have the oil pan and valve covers pulled just to clean everything out. Even then, it was impossible to get it all. The oil return passages in the heads get restricted to the point that the oil light will come on, even though it is not low on oil. Oil gets trapped in the upper end, not draining down fast enough to feed the oil pump.

You might pull a valve cover (whichever one is easiest) just to make sure the engine is clean inside. I would if it were mine, just for the peace of mind.

On another note, I have never torn down a windsor engine with significant miles (over 75,000) that didn't have at least one cracked piston skirt, usually more than one. Probably due to the short rods putting too much stress on the skirt. Although, I am thinking this is more of a problem on the 289 / 302 engines. Just can't remember that well.

Bottom line: if the inside is clean and it isn't using much oil, just keep the "proper care" going, and it could have many miles left in her. 150,000 wouldn't surprise me.

Good luck.