Locked up Slant 6

So I recently purchased a 66 Dart with the 225 "charger" slant 6 under the hood. I purchased it because it is very complete and the former owner was a((Is a)) marine. As a young vet myself and this being the first car my dad ever let me "drive"((say in his lap and pretended to drive)). I grabbed her.

The motor is seized up. Big time. Last known drive was 75. I've let marvel mystery oil and a mix of wd40 and liquid wrench sit in the cylinders for over a week now and haven't got the engine to budge even a little from the crank yet.

I need to find a another slant 6 225. I figured this would be the place to start.

Mopar or No car!
Where about are you located?