I like the AlterKtion because it eliminates the need for the stock upper shock mount.
Mine is a '65 with W-9 heads.
I started with a kit for late A body headers from Stahl and don't have pics of the finished product , but they turned out pretty O.K.
The primaries are a couple inches longer than optimum and one tube on each side still goes outside the rails ( 7 & 8 ), but I got a good stretch of tube before the first bend.
The steering shaft needs to come out for installing / removing them , but I am happy with the results.
Not cheap either , but a lot cheaper than having them made....with flanges from SPD and the kit , I had around 650.00 into them.
Got them coated locally and bartered on part of the price so I am into them for under 850 bucks......well under 1/2 price of having them built.