[TrialbyError]

Hey there, I'm wondering what this plug-in is that is inserted into one of the freeze plug locations on my block. See the picture below. The engine came out of a ford f150 (either a '77 or '79), but the block casting says D4DE (1974 Falcon 302). Thanks for the input!

[onebadblueoval]

looks to be a block heater. used to keep the engine warm when parked in very cold temperatures by heating the coolant inside the engine. usually see that on diesels... never on a gas engine. but i guess if it gets real cold in some parts of the country. i wouldnt know.. i live in california. could also have been placed there just to plug the hole if a freeze plug popped out.

[Ivy66GT]

Originally Posted by onebadblueoval

looks to be a block heater. used to keep the engine warm when parked in very cold temperatures by heating the coolant inside the engine. usually see that on diesels... never on a gas engine. but i guess if it gets real cold in some parts of the country. i wouldnt know.. i live in california. could also have been placed there just to plug the hole if a freeze plug popped out.

William,

You must have never been to Calgary; in the winters it gets cold. The windows there are TRIPLE pane glass, not double.

I agree, it might well be a block heater. In a freeze plug is where I would expect to see one.

A block with that casting number could have been used in anything for which Ford sold a 302. At any particular time Ford would normally have had only one or two casting numbers for every 302 block they made.

[TrialbyError]

Yeah, you're right about the winters here! We only get 3 months of hot weather if we're lucky. This year hasn't been great. Got snow in June hah!
So your saying that the block could be original even though it's from a few years earlier? From what I can see, the date / casting codes are kind of all over the place. I'll see more when I take it apart this winter.