1/1/15 6:08 p.m.

So I'm going to be doing a enginf and transmisson swap in my spit. Ive come to learn that the diff will also have to go. So from what I've read I see the r160 is the way to go. The mouting plate is goning to be made locally for me. My question is with the axles. The r160 I know has to be the type with fixed stub axles.

Now from what I gather I need to use the half shalfs from a old 240z/510s. Is there anything else I'm missing?


spitfirebill PowerDork
1/1/15 6:54 p.m.

This interests me greatly. Keep us posted. I was thinking the diff you wanted was from the 510. Getting hard to find now.

erohslc Dork
1/1/15 7:32 p.m.

Here's a long running thread that you may find useful:,720316,page=10

Post #136 describes a Group Buy (closing January 12, NFI etc.)

The 'rear plate' is very rare, basically unobtanium, some folks have searched for years to find a raw
casting, then are faced with finding someone to do the machining.

The 510 diff uses stub axles with UJoint flanges similar to Spitfire.
Later Subaru R160 used stub axles that mated to CV tulips, while recent Subie use regular CV having an integral stub axle on the tulip.

There are a lot of variations of axles, ratio, LSD, so choose wisely.

DLD New Reader
2/2/15 11:44 p.m.

We are building a 64 spitfire and using Toyota Supra Mk3 LSD. We got a 91 turbo roller for $150.00 that had an engine fire and was pretty well picked over, but still had all the suspension. It's wider, but we're planning on using IFS Toyota 4wd axles (they are much shorter) to keep the width in check. We'll start a build thread here when we get started on the real work. So far we're gathering parts. This is for the $2015 Challenge (or the $2016 if we run out of time). Oh, and the Supra diff has stub axles with a 6 bolt flange to bolt the tulips to, so it can be adapted pretty easily to other axles.

Curmudgeon MegaDork
2/3/15 12:46 p.m.

The early R160 diff with the 'bolted in' stub axles are what you seek and no they are not common. The bolt goes all the way through the stub axle and into the diff spider gear. Bolt in spider gear on the left (duh).

I have heard tales whispered late at night around the campfire embers that some Subaru R160 and R180 diffs have this setup too but I have never seen one.

The problem: the Spitfire design swing axles try to 'pull' the stub axles out of the diff and the vast majority of IRS diffs have 'pop in' inner CV's held by a wire snap ring. That means as soon as the axle 'pulls' at the CV it's going to pop right out.

On the Abomination and also on the current GT6 project, I had to add upper and lower control arms so they accept this 'pulling' force. No it ain't easy.

erohslc Dork
2/3/15 3:59 p.m.

You still see the Subie R160 with stubs on eBay (that's how I got mine), no 'modern' car builder wants them, so they can be had reasonably.
The Datsun 510 stub axles with bolt-on UJ flanges are the rare birds.

BTW, Datsun 240Z used R180, these are a bit larger and longer, and the NZ cast rear plate does not fit.
Fitting R180 to Spitfire with swing axles requires surgery because the diff axle centerline has to match up to the wheel centerline (else you get toe in/out).

But once you choose to abandon the Spitfire swing axles in favor of an SLA suspension, you no longer have
to worry about exact diff axle centerlines so R180, R200, etc could be mounted a bit forward to clear the Spit frame rear crossmember.

In fact, the original model 240Z had the diff mounted forward, the axles angled back a bit to the wheels.
This proved problematic with the UJ based axles of the day, and in subsequent years they moved the diff backwards to line up.

CV axles don't have such issues, they can easily tolerate axial, radial, and angular misalignment in any plane.

evildky Dork
2/4/15 10:15 a.m.

The 240Z did come with the R180 but the half shafts share a bolt pattern with the R160 equipped 510, at least thats how I remember it.

DLD New Reader
2/25/15 9:37 p.m.

FYI, I started a build thread for our Spitfire. No real building yet, but some photos of the Supra suspension/diff you might be interested in. Look for it in the build thread area, it's "Another Spitfire Build"

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