When I put the new motor in my 85 I got another pan from a buddy (so I could keep the old motor intact and sealed up as it still ran) and that 2nd pan had the dipstick tube still in the pan but at some point it had cracked, and been brazed solid into the pan receptacle, it broke off while I was cleaning it up to paint. That was a major pain to get the stub out and get the excess brass (brazing rod) off so I could get the stub out and put the truck's original tube in this pan.
The tube slid right out of the old motor. .
Yours being a truck motor it does have the hole in it (in the block) for the dipstick tube it would have had if it had started out as a "car motor" but it's got a plug in it from the factory.
My "new" /6 that went in my truck was originally a car motor, so I had to plug that hole. I bought a box of 3/8" freeze plugs (only needed 1 but not a commonly asked for size so I had to buy the whole box/ but it was less than 7 bucks for the box)
Now this 64 motor I currently have on my engine stand, was originally a truck motor, but back then they had a front sump instead of a rear sump like 72-up trucks had. Now that pan is really hard to find. But that dipstick tube goes into the hole in the block intended for it, (as if it were originally a "car motor")
I swapped the pan out and after I had the "new" pan back on I thought about pulling the tube out, but it won't budge. I should have knocked it out from within while I had the pan off.
That motor is going to a good buddy of mine and is replacing a 170 in a same year valiant.
