Do you have factory power steering? Or an aftermarket rack and pinion? Any plans on upgrading to either in the future? Or to a Manual?
Those will need to be answered before you purchase a set, or you will be buying another set later. The shorty style headers are pretty much a guarantee to fit any thing.
For long style headers with factory power steering, you will need a power steering cylinder drop bracket. This is not big deal, just a few bolts to lower the P/S cylinder to make room for the header.
If not, any decent quality header made for a 66 289 (since they didn't come with 302) will work. The 84 302 should be dimensionally same to a 66 289.
The biggest recomendations I can give you is - DO NOT GET A CHEAP HEADER! THEY WILL LEAK, AND THEY WILL RUST QUICKLY.
Try to find one with a 3/8 header flange, and a good coating. If you dont want a ceramic coating, you can skip this and paint it yorself with some header paint.
Also if possible get a ball type socket at the collector. The 3 bolt flanges warp and will leak. Some have 3/8 inch flanges at the collector, those should be ok.
This brand is one of the more expensive, but the quality is there, and they will give you a header that fits and tucks up nicely to the floor boards. check out FPA, Ford Power train. I run their headers on my 69.
Excellent Fit, quality, and coating. They have 3/8 flanges, with ball sockets on the collector, and came with good quality header gaskets.
And my favorite part is that I could Properly get a 3/8 inch socket on all of the header bolts when installing - a very rare occurrence with almost any other header.
If you are going from stock manifolds, you will need to get some 3/8 inch ARP header bolts. If you have aluminum heads, use anti seize on them. Re check torque a few times after the install, then periodically during regular maintenance.
