Why 1.75" primary... engine specs?
I can tell you now, do NOT buy Hooker Super Comps.
I have a 12 year old set that fits well... but the last couple sets I've installed in others cars with the last 2 years were terrible compared to my old headers... the welding quality is terrible and the fit is even worse. I think their jigs are old and beat to hell and it shows.
The newer production hooker headers had flanges welded on crooked and the collectors pointed
UP right into the floorpan. We had to put a 10' stick of tubing into the collectors and have 2 guys hang from it with the car on a lift to bend the headers down so we could put pipes on them and clear the factory transmission crossmember.
Stahl makes a nice fitting SBC header for A-bodies, but have your wallet ready. Probably the best fitting and fit/finish of any "off the shelf" header I've tried.
http://www.stahlheaders.com/Web101P_1.html
Depending on your engine specs 1-5/8" may be a better match-- in which case I've had good luck with the fit of Hedman and Dynomax on A-bodies and the price is right.