as far as i know the only differences between egr and non egr late model 240's is the

1. the egr ecu
2. the egr exhaust manifold which you simply plug after
3. intake manifold
4. egr valves and detritus
5. can not recall if the cylinder heads vary

if it was me i would pull the engine and transmission from the rot car swap it into the good one whole. then plug the ports in the exhaust manifold for egr or swap the non egr manifold and do the same for the intake. the exhaust ports are 1/2 inch something. if the head has ports which i think it might but just don't recall simply plug them.

fyi interesting technical data on cylinder heads

http://people.physics.anu.edu.au/~amh110/Head/cylinder_head_531_530.htm