According to this Wiki article; https://en.m.wikipedia.org/wiki/Chrysler_LA_engine chamber size is 62cc.
Also found this: from here: http://www.moparchat.com/forums/ram-...m-engines.html

 

In a word NO, Best you can do is find a mopar performance pcm for your engine. That's if you can find it! Some are available and some are not. If you get lucky you may find one on ebay. MP made these shorty after the engine/trucks came out and they where only produced a few years after that's why that are hard to find. And they are not for heavily modded engines(strokers etc..) Before you plan on what engine to build you need to figure out what's going to control it. I think finding a OBD2 pcm and harness would be an option unless you go with an aftermarket controller. If i may add my $.02 worth if you are looking for performance there is no replacement for displacement (as long as it's not forced induction) as you read before. So why waste money on the V6? Ever consider a hemi swap?