My guess is that you aren't going to get a 100% answer to all of your questions because it would involve a person responding who uses your exact same setup.  Given the myriad of possible clutch linkage, head, and steering options for classic Mustangs that's a taller order than it may initially seem. 

I can tell you what I know, which is that on my '67 the cable clutch routing was a non issue with the headers.  Spark plug clearance was good, but I had to go to 90 degree boots to clear the tubes as the straight boots that most of my existing wires used hit the tubes.  That is with stock heads though, not sure the angle on the AFR heads vs. stock. 

I run a Borgeson steering box and Sagniaw pump setup on my car.  The box and headers had an interference issue that required me dimpling the LH header on one tube to clear a bulge in the box.  This was not an enjoyable process and required installing and removing the header 4 times to get the right amount of clearance without over dimpling the tube.  That being said, and without first hand experience, I don't think you'd have any issues with a R&P setup because the problem I encountered had to do with the box being in close proximity to the header.  On an R&P setup that same area will have a relatively small steering shaft, and possibly the top of the rack where the shaft goes in.  That configuration is nowhere near as big as my steering box, which only hit at the top of the box (farthest point out from the framerail).  Were I to bet on it I'd bet it will clear with no problem. 

As far as X or H pipe, I wanted an X pipe, but JBA only offers an H pipe.  I also wanted 2-1/2" Magnaflow exhaust, which comes with an X pipe, but no ball and socket connections for the JBA headers.  There are multiple solutions to this problem, but mine was to buy the JBA H pipe and cut the down tubes coming form the headers off such that I could then connect them to the tubes coming forward out of the X pipe of the Magnaflow exhaust.  This was probably a more costly way to go vs. going to an exhaust shop and having it fabricated, but I was able to do the job at home in my garage in a day.  It also kept welding to a minimum, as I joined the pipe with stainless wrap around clamps.  I did have to weld tailpipe hangers onto the Magnaflow exhaust, but there's no real getting around that.  I also fabricated upper mounts for those hangers and modified a set of GT tips with rolled lips to mate to the 2-1/2" pipes and fit perfectly into the cutouts in a stock valance.  Without the trickery you could have probably gotten away with clamp on hangers and no welding. 

I'll also add that its too much to expect any aftermarket equipment to just bolt on.  After decades of wrenching on cars and trucks I can literally count the products that did that on one hand.  Asking a bunch of aftermarket stuff to play together without some amount of work is asking even more, so be prepared to do some work.  With these older cars even a guy with the exact setup you have that had no issues doesn't mean you won't.  The tolerances on these cars are huge, and then you factor in accident damage, rust repair, etc. and it gets even worse.  At best you're going to minimize it. 

John Ha wrote:

. . . . .I finally got JBA to believe me and they sent replacements with the correct pattern.  Don't know what happened there - pretty sure that's a problem they no longer have but they do have good customer service once you convince them that they have a problem.
 

I installed the H-pipe mid section from JBA which had O2 sensor bungs welded in on the bottom side of each tube about 3" below the header attachment. When I contacted them about it, they refused to accept responsibility for the incorrect placement despite the photos I sent and claimed that I must have put them in wrong. It cost me another $60 to have a bung installed in the correct location after abandoning the two worthless bungs that JBA claims that they never installed! That's not good customer service.

Last edited by rhutt (1/06/2019 5:54 PM)

Thanks, all. I appreciate the detailed responses. I’ll check out Sanderson too, but based on the responses here and at VMF, I think I’m leaning towards FPA at this point.

Another vote for FPA's, great quality and ground clearance but you pay for it.

Information that would have been greatly appreciated BEFORE I had the set of JBAs and was trying to install them on the car.  Now I'm more pissed than I was before.  If it was an oversight, fair enough, you can't test every combination out there.  But what you're saying is that they know the headers don't work with the Borgeson steering system and choose not to make that information readily available.  Seriously, all it takes is a little note on the fitment guide.  Other header manufacturer's seem to make a half dozen fitment notes on their headers. 

I bought a set of FPA hedders from Stan and I can't speak highly enough about his products and himself.  He offered to send me a set of hedders first without my paying for them and trusted me to pay for them if they worked.  The fit to the heads was perfect.  I screwed the bolts in by hand.  (Try that on some of them others)  I only had to do some rework on my chassis due to other than stock engine I was doing, but the hedders are really perfect for fitment and Stan was great help.

Well, the FPAs arrived this week and I installed them today.  This might be one of the rare times where you really do get what you pay for. They are very well made, were super easy to install and fit absolutely
perfectly with good clearance for everything.  By far the easiest set of headers I’ve ever installed. And they tuck up really tight, in fact the bell housing is closer to the ground than the headers. If your budget can stand it, I highly recommend them.