damn those are expensive, try here theyre half and stainless as well.
O2 Simulator, mini catalytic Converter cel fix

 

Even cheaper than that are the anti-foulers from the parts store. You just have to drill larger holes into two of them (you have to stack them).

 

But michael ive found you need to use the 90* fittings not the straight ones to fit on jags and many others, and the parts house ones ive seen are reg steel not stainless

 

Next time Im under my car I'll have to take a pic. I dunno if the STR is different, but I didn't have any clearance issues.

 

The stype generally have more room than other jags and remember many times i comment generally since i cover most all subforums in here. Matter of fact i usually dont even know what subforum im in. Has burned my comments more than once. That aside i also prefer the extra wiring harness room the angled spacers give too and like to put them facing the engine