Why put on flares? With the right wheels you can put all the tire you need and keep them inside the stock wheel wells. The correct way to install the pre-L bumpers is to fill the rather large holes left behind when the L bumpers are removed. And find the pre-L bumpers, of course. They're getting a bit rare.
By rally, do you mean like WRC rally? I'm not sure I'd rally a "not a full restoration, but really close" car. But, hey, its your car and your $$$.
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