In reply to:

(the LP and NG grills use fundamentally different burners).


I've also heard success from the nat gas jockeys (the guys that do installs) that simply boring out the venturis works for converting a propane to nat gas. I can't speak for how well it works... I've eaten food off their BBQs and it seems to work well, but with no first hand experience - I can't say for sure.

Bren R.