300 six question

[Lenz]

Picked up a '69 F100 with a 300 that runs perfect (don't know the year), but when nosing around I spotted an odd plug in the block just aft of the oil filter, north and down from the oil sender.  Plug was only in a thread or so and the wrong thread to boot, looks like a passage to an oil galley.  Can someone put me some knowledge what this threaded boss is for and/or the correct thread size?  Looks roughly 5/8ths diameter, "finer" thread.  I'm looking for the right thread designation to plug it properly, but I'm also wondering about the purpose.

[machoneman]

Wow, it's been a long time but...are you sure it's not a water jacket drain? 'Course now that I said that I don't remember where the oil sending unit, hence an oil passage, is located on your six.  Btw, if you have it out, I'd dig with a pick or other object to see if trash has plugged the hole. Old Chrysler V-8's were notorious for having so much rusty sludge in the system that one could take out both drain plugs and nothing came out! 

[Lenz]

Thanks for the shout Bob, it's a clean, large threaded hole going down at a sharp angle toward the oil pan.  No sign of corrosion or crud anywhere when I popped the plug out, looks oily inside and there's an oil film and build-up around it.  I'm thinking I'll pull the coil wire and have someone crank it over to watch.  Wouldn't care about it except if it is a port to the oil galley I need a lot better plug fit.

[GJCAT427]

Lenz, could it be for a screwin dipstick? Some of the bigger trucks may have had them. It may still have been for a pressure guage

[Lenz]

Could be Garry, didn't think about that and the angle suggests that possibility.  Don't know where the block was sourced and they used these 300's in everything (a "ton" of UPS trucks too).  That's why I posted the question here, always a chance it would throw a switch for someone who knows.  I'll shove a length of wire (the same calibrated wire I used to measure the stroke )into the hole and maintain the angle, that'll tell the story.  If I find the pan then just plugging the non-pressurized hole will be a simple matter.

[jayb]

I think Garry's right, probably for a threaded dipstick tube...

[GJCAT427]

Lenz I had my eye on one of those 300s that was in a F600 from the early 70s a couple of yrs ago. I can`t remember if it had a screw in dipstick. its long gone now so I can`t even check. I do remember it had a huge oil pan like a FT on it. Those engines we some kind of tq monsters!

[Lenz]

Yep, right down into the pan Garry, simple plug it off operation.  Now all I need are wiper blades, this thing was a great deal.  Its what I'm gonna run when I'm not running the Galaxie next year and they aren't salting the roads. 

Put a lot of miles on the 445, running great and I drove it everywhere, covers with people wherever I go.  Might be the idle, the stance, the black on red?  I've been told it's how it sounds going by.  Don't know, cause its just a 20 footer but when the 20 year olds step up it bridges the gap.  Bagged it for the winter, needs nothing so now I can fool with the F100 'till spring.  Of course, if I get my plate before it snows to salt the roads its going to town... .

Love the 300, had one in a '77.  Torque all in at <2,000 rpm with 7 mains, can't break one.  That's why UPS loved 'em, a guy running a stick couldn't stall one if he just took it off idle.

Thanks for the input all, got me thinking enough to get to the answer.  That's why this forum works.

[GJCAT427]

Lenz, I finally got the galaxie running again, only to discover a yellow jacket nest in the right frt fender where  I was working over! They aint gonna survive the winter in there! Taking steps to eliminate them now.

[Lenz]

Good news on the Galaxie, hope it was cold enough outside when you found those jackets.  Sure is a lot less painful than when they find you