I've been working on the J-H project for a while now, thought I'd post my progress.
The front suspension was pretty time consuming. The original setup had no camber adjustment provision so I had to modify the upper control arms. Here's the front suspension about halfway figured out. The outer tie rod end is Miata, I only had to run a 1/2-20 tap to clean up the threads and they spun right onto the J-H inner tie rods. This fixed the original bump steer quite nicely.
Here's the front suspension assembled and ready to install. The shocks are QA1 coilvers with 550 inch pound springs.
The stock J-H rear axle has no aftermarket. So I decided to narrow a RX7 GSL rear axle; 3:89 gearing,limited slip and disc brakes. The stock J-H axle is 54" drum to drum, the RX7 piece is 57 3/16". So I had to narrow the rear axle. It was a crappy rainy day today so I got busy disassembling the rear axle and cutting off all the stock RX7 bracketry.
Here's the RX7 housing after all the brackets were stripped, the bearing carriers were removed and the housing was narrowed. I have to build a jig so I can keep everything straight when I burn it all together. I got the inspiration for this part of the project from this Web page: http://the-mite.com/mite22.htm Many thanks to aeronca 65t for pointing me to that site!
I have to send the axle shafts to Dutchman Motorsports to be cut and resplined, I will also have them redrill for the Miata 4x100 mm bolt circle.
Next up: convert the RX7 bellhousingfrom hydraulic to cable clutch. This will involve moving the pivot to the opposite side of the bellhousing. Should be fun.