Albrecht
Well-Known Forum User
As always, I defer to your far greater knowledge and am more than open to suggestion regarding period correct 5 speed box. 280ZX just seemed a more common upgrade and, I thought, possibly more available than an earlier box.?
I wouldn't claim to be any kind of expert on the 510-series cars, even if I've always admired them.
One thing I believe you'll have to watch out for is the respective gearbox lengths. I think I'm right in saying that a 4-speed equipped P510 would have been fitted with a '63' length gearbox (Zs were '71') so when putting in a '71' you have to deal with the big difference in shifter position.
Nissan used to sell a 'Sports Option' kit to install the FS5C71-A transmission into the P510 body, and it included a different trans mount, a shifter kit and a new propshaft. I believe they did the same with the 'B' type 5-speeds a little later, so they *do* fit and hopefully you would not need to do too much chopping around.
I think your R160 diff ratio will already be a 3.9:1?