Help me identify this 360!

[str12-340]

A buddy of mine bought a 68 Dart that was somebody's project. He was told that the motor was a Moper Performance crate motor. It has a Mopar Performance dual plane intake on it. It ran pretty good so he just took it at face value. Now it looks like it needs a rebuild and I looked at the markings on the engine. Can anybody help me decode what this thing is?

Cast on Drivers side of block: 3418496.8.36
Cast on passenger side: 8.25.71
Cast on Head (where I might look for an X or a J) is 21

 

[Locomotion]

Not sure if they were already using seasoned blocks when the crates came out or not. Being a '71 block, it would appear to be a Commando 360 with rocker shafts. The dual plane would indicate the 300hp version which had 1.88" intakes and a .474" lift cam. The 360hp version had a single plane intake, 2.02" valves and a .484" lift cam. Head casting # would be on the underside of the head on the intake side in the valley area. I believe they used 308 heads, which were part of the later heads with the big pushrod holes.

 

[Rocky_JS]

look on left front of block under the head are there numbers there? also along the pan rail right side midway there is a pad what are those numbers?

Cast on Drivers side of block:

3418496 is block cast number 71-4 360,
-8 is a casting revision number,
36(0) it really should read 360

Cast on passenger side: 8.25.71
= actual casting date of block

Cast on Head (where I might look for an X or a J) is 21
? might want to pop a valve cover and get actual casting number or someone else can answer this.

 

[str12-340]

Thank you Myron and Rocky!

Any other insights?

 

[Rocky_JS]

No, based off of the info given that is about it.

If you get me the other info, if any, that would pretty much tell if an actual crate engine or not.

 

[rumblefish360]

The letter head series of heads have the letter cases I to the head right near the spark plugs. The casting numbers would also be good to know. In general, they'll all port out the same within a few CFM.