This is solely speculation. Theoretically (it hasnt been tried) the ralliart engine will drop in to the body of the lancer... nobody has done this but in theory it would work. Upon reading about the new eclipse... the engine for the inline 4 is the same engine as the ralliart.. the 4G69 I believe. If the chassis/frame for the GT and the GS new eclipse is hte same.... would it be possible to drop the V6 into the frame of the eclipse GS... and if the engine is the same as the ralliart engine... could the eclipse GT be swapped into the body of the lancer if the Eclipse 4G69 engine would bolt up to the body of the ralliart? Nobody knows yet if the engine mounts/etc are in the same position but I do know it is the same engine.

Cliffnotes.... New eclipse GT engine dropped into lancer?

 

Might be too large. The FTO/GVR4 6v12 is the only one that I know has been done successfully so far. Even with a smaller displacement 6 like thet 6v12 (doesn't necessarilly mean smaller in size however) clearances were tight. There's a pic or two of this on RPW's website.

 

It won't help with weight distribution. It will be even more front heavy if you can shoehorn an Eclipse V6 into the engine bay. Bad for handling.