Difference between Volvo D13A and D13H?

What's the internal difference between VOLVO D13A and D13H engines? Is it possible to swap ECM from D13A in to D13H engine?
My intention is to build pre-emmision Volvo D13 engine, without EGR and without after treatment system.

 

That's what I thought, before I saw a few trucks with ECM TUNE dellete and completely delleted emmisions, with burned pistons in D13. They are saying this engine doesn't like those dellete aftermarket tunes. But I checked D13A and D13H have different camshaft part # so they are different inside. And Volvo D13A was pre emission engine

 

So that shop started to leave factory ECM program and they just connect emulator to eliminate DPF and DEF system. But going this way you CAN'T eliminate EGR system. If you leave factory ECM program and EGR system intact seems to work just fine BUT NO power and NO fuell millage gain.

 

I'm talking about D13H engine. This is North American version but they had in Europe D13A version without emmision junk. So I'm thinking what changes should I make to the engine to change it to D13A version. As far as I understand I need to do few changes:
-ECM or just reprogram.
-exhaust manifold and turbo.
-camshaft.
Who knows what else is different??