If your numbers are correct, that's not the original motor. The letter in front of the 440 tells the year, I.E.: C=67, D=68, E=69, F=70

 

on the 415 h. is the h barley decernable? if so and theres a p after it, then its a 70 hp block assembled on april 15. 1970. if so then the blocks still desirable due to the hp stamping. if the cars in decent shape, and the price is agreeable to you, then is consider it anyway, finding a matching nmbs. car at a decent price is geting harder to do. Id try to leave a few options open. just my thought.

 

look in the front of the engine, on a flat ridge, to tell you what year the block was used

 

yea the #s areC=67, D=68, E=69, F=70

 

Here it is kids
X= 66-70 Charger
S= Charger RT
29= 2dr sport coupe
L= 440/375 hp 68 & 69 only
9 = 1969
B= Hamtrack Plant.

The 2536430 ,LO is probably LC for low compression. But the casting # is 440 from 66 to 72.