Hi Rivi enthusiasts......I am considering purchasing a 2nd gen. Rivi. I wish to add air ride, lower the stance, and find 18" Buick style Rallye wheels and a tuned exhaust. I want it to have a throaty rumble outside but quiet inside. My question is this. If money were no object would you rebuild the original engine and add fuel injection and electronic ignition? Or would you drop a modern crate engine in it? Though I am not a hot rodder I've heard plenty of car talk and I've never heard anyone praising the Buick engine like they do Chevy engines. Why is that? And what does the term "nailhead" refer to? I assume it describes the cylinder head. Thank you all in advance for your opinions! G.C.