Most of the narrowed front rigs I've seen are tube-framed buggies, and some of them have engines in the back, or rear-mounted radiators. I sometimes think they kept the grill -sort of - just to keep Jeep sponsorship.
It seems like a big project, possibly involving months of misery and mucho bucks. Keep us informed if you do it! Ain't nothing good on TV anyway.
How about lowering the hood line, like the LowerForty?