I'm needing something beefier than the stock H145 for my 1200, but nothing crazy. I'm putting a 1.8 Miata motor in my car and I'm not sure what the best option in. I was hoping to get suggestions from others here in the U.S. based on my thoughts.

Option 1: Ford Explorer 8.8 w/posi+disc brake. Would need to be modified and smaller axles fitted.

Option 2: Full custom axle built by Curry or other. Seems like the cost just doesn't warrant having a solid axle still.

Option 3: Miata rear subframe fitted to Datsun. Would allow for LSD, disc brake and IRS.

The goal with the car is track days mostly. I'd really like to have an LSD and disc brakes, but could live with still having leaf springs in the end I think. Can anyone thing of a better option for me?

Ford Ranger 8.8 with stock axles fits the 1200 width-wise. Mazda B4000 and Ford Ranger 4.0 1990-1992 have the shortest 8.8 with 28-spline axles (1993-up are 1.5" wider). Obtain an additional short-side axle and cut only one side of the axle housing to narrow it. Door tag AX R6 indicates axle tag 3L73 (limited slip). Axle bolt pattern is 5-on-4.5" (same as Nissan S14)

But that's crazy strong and heavy

For IRS, several have been used on the 1200

Datsun 510 with Subaru diff, LSD is easy to find



Subaru disc brakes. Bolt to leaf-spring eyes and rear mustache bar. Custom A-arms



S14 (Nissan 240SX) narrowed

there is an old mustang 8 inch diff not 8.8 its the hilux equivalent but available with strange alloy carrier otherwise H190 with LSD sourced from me :) or locker type lsd from US supplier

if you look at racejunk there are all alloy quickchanges from 600-1200usd the best of the lot for live axle, miata is a bit heavy I would have thought

If the Miata motor is reasonably stock, wouldn't a H150 from a B210 be strong enough. I seem to remember other American members using it in front of an L18 in a Coupe. As far as I know, they are the same width as the H145.

Good question. 1st Miata 1.6 was 100 ft.lb. torque. An H150 can handle that. The Miata 1.8 was 122 ft.lb. H150 can handle that

1975-1978 B210 rear axle assembly bolt right into the 1200 (though sedan and coupe differ). LSDs are very rare, but disc brakes can be fitted

how about ae86 lsd into 1200 h165 ute?

We don't have ute rear axle assemblies in the US. But that's a great option, disc brakes can be fit too

Could use 410/411 rear axle assembly, a newer H165 center section that works with the TRD LSD, and the Rear Disc Brakes. Only we don't have newer H165 center sections in US, but if the 410 axles are the 28-spline, could do the AE86 LSD Swap

Narrowed Ford rear ends are the mostly widely available and would be inclined to go that way.

The Miata rear suspension is very good and all of the parts widely available, I wouldn't worry about the weight as it is the least of the issues. If the Miata rear sub frame will fit under the car, the next issue is going to,be how you resolve the bodywork and how are you going to widen out the front suspension to match. The track on a Miata is something like 6-7 inches wider than a 1200. The rear inner fender will need to be cut and rewelded to the bodywork to keep the structural integrity.

I went with an H190 on my car; the LSD unit itself was $1300, I picked up a 1200 project car with an H190 so that I would have all the little bits and pieces for,the conversion. I was able to sell of the left overs and cover most of the cost. I'd have to double check my numbers but I think all said and done it cost me $1500-1600.

You can probably find a complete Explorer rear end for $300-400 and then order a custom housing an axles. I'd still expect that to run you $1000-1500 depending on what deals you could find.

The H145 will survive a stock Mazda 1.8 is you are mindful of standing starts and how you shift. If you are going to Rallycross it and sort of wheel chatter will do in the H145 rather quickly.

The Miata engine is a 1.8 with a slight overbore and custom cam so I'd probably have to go easy if I used a H150. In the end I'm expecting ~170HP though I'm not sure on the torque number.

The other part I forgot to mention is part availability. I know in the wiki it says Ford Rangers fit when shortened, but after 6 months of looking I have been unable to find the holy grail AX R6, axle tag 3L73 4x4 4.10. I've found other axles that could fit great in theory but again can never find the right combination for sale. AE86, Celica/Supra, Volvo 1800, Volvo 242, RX7 GSL-SE. They can all work but I could never find the right combination of LSD, disc brake and a higher end gear ratio.

At this point I was just looking for other possible options that I might have missed so I can get this thing going. Money isn't the issue although I'm not going to just spend like an idiot. I did research a full custom rear end from MADDAT or Curry but the prices are insane.

Thanks for helping with the brainstorm...I'll keep looking!