Did your JBA headers look as crappy as mine?I just finished up my JBA header and catback install. I encountered the same problem on my 4x4. I was able to access the back bolt by tightening the front bolt(17 mm) and loosening the 4 bolts on the engine. Then jacking up the engine again. That created enough space to get a short 17mm socket on the rear bolt to tighten it. This was a problem on both sides. The header crosses directly over top of the back 17mm bolt. My clearance was fine on both sides once everything was tightened.