I purchased these from Thornton a few years ago and have been running them on my '69 442 (400G). Replaced the original WZ manifolds and these did everything Thornton claims. Fantastic quality - all welds, flanges, etc. They fit perfectly (car has AC, PS, TH400) with zero modifications required. I'm building another engine with Mark Remmel and will be switching to full length headers so these are available.
I recommend you visit Thornton's website for all the details. They're 304ss and I purposely bought them 'natural' (not polished). I run a 2.5" exhaust with Pypes downpipes and these fit like a glove with no issues. $375 plus shipping.

Thanks for all the interest in these. They have been SOLD.

 

Sending pm. Greg