I have 2.5 turn lock-lock steering boxes (instead of the 4 turns lane-lane, (exaggerating) for the stock box) for almost 1/2 the cost of the top 3 rebuilt steering box/upgrade rebuilders. They come with a one yr. no mileage limit guarantee. They are the proper"808" original type boxes with the original feel. Can ALSO add the firm feel, but EVERYONE so far has been completely satisfied with the original feel boxes. These rebuilt boxes ARE A BOLT-IN swap for ALL Full size cars & Riv's from'59 Caddy to '76 B Body cars. No adapters, hoses or ANYTHING SPECIAL needed. Almost feels like rack & pinion steering in comparison to the original. I ALSO have Poly lower control arm bump stops & strut rod bushings. All of which I have in stock. I don't remember if the rear of the '66 has a Panhard rod or not, but IF it does I ALSO have those bushings in stock as well. Addco makes 1 1/4" front sway bars & 1" rear sway bars. I have Bilstein shocks also. I would NOT use Poly bushings for the front upper control arms. Between the steering box upgrade, sway bars & shocks will improve the suspension (& PROPER) front alignment specs. improve steering feel greatly!!!!
Tom T.