440 engine for a 1968 Charger - some questions for the group

[WikedCharger]

Good morning, Over the weekend I bought a 440 engine that I hope to use in my 1968 Charger. The engine is dated 5-19-77 so I'm assuming from a 1977 or 1978 motorhome. The cylinders look good and the engine looks complete. The seller had it stored for several years in a garage with a cover. There were no spark plugs in the engine. I tried installing some old spark plugs I had left from a 383 engine but they don't seem to want to thread in. The threads all look clean but it almost seems like the spark plug thread length is too short. The 383 seems to have the threads right at the edge of the head whereas the 440 threads seem to be countersunk. See pictures below.

Also, I noticed it looks like there is a small hole in the intake under where the carb mounts. I plan to switch the intake but thought that was weird. I've also added some pictures of the engine for reference including the block pad stamping. It looks like it says 7 T 440 E.

Thanks in advance for any comments.

 

[ckessel]

You'll need a "Peanut" plug for that. Like a 25 Autolite or equivalent. The hole in the intake could be a rust hole that goes into the exhaust crossover. That should be a cast crank engine. Will have a counterweight on the balancer that says "for cast crank only". That affects the trans end too. You'll need a converter will counterweights, if auto, or there are flex plates you can buy that allow you to use a regular non weighted converter. The flex plate looks like a bite was taken out of it.
Flexplate 6 bolt - Cast Crank - Automatic Transmission