R180 diff? Something seemed off and the car's geared really short... best avenue to fix?

[demo243]

Previous owner was an... interesting... fellow. He fetched quite a few parts from other junkyard datsuns... L18 (from a truck?), 280zx five speed, and now the rear diff... so bizarre. This car has been fun to work on (for many reasons!). Who knows what else I haven't found yet that's different.

Thats the beauty of these cars! They are kinda like legos, you can build em one way, tear em down and build em another. And its amazing how many parts are compatible off other/newer Datsuns and Nissans!

L18, 280zx 5-speed, even the diff swap are not uncommon swaps. These 510s took a back seat to the Z cars back then so alot of the mods seem to have been out of need, availability and cheapness...

[shaddai]

Thanks all... my son and I jacked one wheel off the ground and spun it six times - the driveshaft spun a bit more than 12 times - per his calculations this means it's a 4.11 ratio diff. This certainly explains a bunch of things!

Now... time for a 3.9 or something. 4.11 is too high for my tastes, I believe.

[datzenmike]

You won't have much trouble selling a 4.11

[shaddai]

You won't have much trouble selling a 4.11

Nice! That's probably the easiest thing, right? Find a new lower ratio diff and swap it in, then sell this one? Better than trying to regear?

[funwithmonkeys]

There should be lots of 3.9s around. Selling a 4.11 should be very easy as Mike said.