J15 and Tranny...

[Kyle253]

Alright so I got a 67 520 and it has the J15 in it and is about as slow as can be in 4th gear. Blew a gasket on my way home from Beaverton, OR where I bought it from. My question is can I mount up the dogleg 5 speed to it? Need to be able to use it on the freeway. Going side streets all the time takes forever.

[datzenmike]

I know of no 5 speed that will fit the J series motor. Whats the problem, just drive it on the freeway. Does it seem like it's revved to the moon and going to blow up??? Or top speed is too slow?

[Kyle253]

Yeah it revs super high. Can't get it past 60. And at 60 it seems like its about to blow.

[BillM]

Your only option for a better gear ratio is to find (good luck!! ) an MGB transmission with the overdrive.

The J-15 and the MGB engine are almost the same (MGB is 1800cc and bigger valves for more power).

You also need the MGB engine backplate,

BillM

[datsun 521 ute]

I did find this is my searchs a while ago as I am also looking to do this in the future to my 521/J15.

http://forums.nicoclub.com/tranny-interchange-t375083.html

[datzenmike]

It's never going to blow up. Just siounds like it will. This is a motor swap as the 520 only had a J13 so you probably have the power to drive a 4.375 rear differential. This is way cheaper than an overdrive transmission.

[chiwag]

I have a j15 engine with 4 speed and I can above the 60mph without problems. will not have problems with time on your engine.

[datsunaholic]

I've done 75 with my J15 520.  However I believe mine has 4.38 rear gears, as the rear end was replaced at least once.

[Kyle253]

I'm not sure what the rear end is to be honest. This is Brian D's old truck and I believe in his build post he said something about a Toyota rear end I think.