V-12 Emission Control Removal??

Back in the 60's, jag's i6's were the sh!t. Than, the US made jag put emission controls on, and they had to use a v12 to get the 250 horsepower back. I happen to have one of the old v12 etype (xke)'s.
I figure, if i can remove or bypass some or all of the emissions systems, my car will see a tremendous horsepower gain.

My question is, how and where do i begin my quest to have a v12 beast that may or may not destroy the atmosphere. :-Þ i have heard of it being done. I would guess a few modifications could yeild a 300+ hp car, or total rebuilding may have me up in the 400 range.
thanks. -rich