The only time you may experience an issue where EGR is causing a driveability concern would be if the egr valve is being opened by a misplaced vacuum line maybe, if the pintle valve is stuck allowing exhaust gas to enter the intake, causing rough running and such. But just eliminating the egr shouldn't cause any ill effects. You can "eliminate" the egr in the .bin so the ecm doesnt even look for it. It isnt electrically connected to anything in the ecm other than the vacuum control valve so the ecm will never know its gone until its commanded and the ecm looks for a change in MAP sensor signal. If it doesnt see the change it expects, it'll set an egr code, but still have no adverse effects on engine performance.

As far as the mods you have made, do you have specs on the "marine" cam? Also, you may have head-to-intake mating issues, but I can neither confirm nor deny that at this point, ill have to investigate that. Do you have the casting numbers on the heads you're using by chance? I know the intake port is slightly higher(raised roof) on the v8 Vortec heads which can cause mating/sealing issues between the head and intake, the v6 may be a similar situation.

I can only imagine how scarce parts are on the island, that's gotta complicate things. Have fun in Reno.

Buddrow