The Quality is A1. Probably the best set of headers quality wise I have ever seen.
The modifications needed to make them work...
1) Motor mount removal, and use of a block plate.
2) Because of #1 and the offset of the II engine it requires centering of the engine and transmission in the bay.
3) Because of #2 you have to rework the Trans mount and drill new holes in it.
4) All 8 tubes run under the A Arms, you need to modify your front springs in order to run on the street. Drag track may be ok but not likely. I think I had 4 inches clearance is all.
5) You have to trim the unibody flange to accomodate the headers.
6) You may want to custom build 8 tubes to bring the collectors in closer to the tunnel, (I did).
Summary: Damn cool headers, Damn pain in the arse, Would I do them again? Probably not, If I was to do it again I would center the motor and buy a set of 302 headers from an early vintage stang. 68, 67, or so and put them on the 351W.
I do have pics if you want to see the finished product, angles and all. Heres a top view. Not the best pic but if you want more I can get them for you.