Based on the info I read it looks like this is a 67 (C on heads)425 Super Rocket. Am I mistaken? Not sure what's ben plumbed into the "drill hole."

 

The hole should be 1/8 NPT for an oil pressure sensor. That casting number is for a 1966-7 425.

 

Thanks! I continued to read and looked at my intake manifold and saw its a 390390 which I understand to be a 4 barrel so not a Toronado engine.

 

If the paint is original, that is also an indication that the motor is not from a Toro. Keep in mind that a lot can happen in 60 years, so who knows if the heads and intake are original to that block. If you find the engine unit number (which should be on the front end of the passenger side head, but may be at the back on the driver side if the heads have ever been off and possibly swapped at reinstallation), that will help narrow down the original application - well, for that one head with the unit number stamp, anyway. 425s could have come with 9.0:1, 10.25:1, or 10.5:1 compression ratio, depending on the original application. All 9.0:1 motors were 2bbl from the factory, but again, the 4bbl intake bolts right on.