I recently swap r180 to r200 3.54 for street/freeway daily driving..but still using 4 spd..My 240Z slightly modded L24/N42 head w/280 valves..etc., big cam, 6 to 1 header, and Z therapy SU..which tranny is best suited with this setup before a I buy a 5spd..is it 77-80 Z tranny (wide ratio) or 81-83 ZX (close ratio)?

I have a 260Z with a warmed F54/P79 ,Schneider 460 270-80 cam, 6 into 1 header,2 1/2" exhaust with 3:54 R 180 ,close ratio 5 speed and the car runs great, the trans keeps the RPM,s in the cam,s sweet spot around 3000 rpm between shifts.

Not sure on the 3:54 diff but I have the 3:90 diff with the 79' ZX 5-speed and it has great Low end and awesomefreeway speeds and Gas milage.

At 80 MPH, the tach is only at 3000 RPM, in 5th gear. Which leaves PLENTY of room for speed and MPG. No real torque at that speed and gear but at that speed, there's always room for higher RPM's and down shifting.

Dave

What was the purpose of switching to a R200 3.54? Seems like a lot of weight gain. I would think that it provides lilttle to no acceleration as is. I'm a fan of the later ZX 5spd with my 3.90 R200. I'm no expert (disclaimer). and probably not much help, either.

adamr

WELL 5spd is 5spd..im not going to split hair between wide and close ratio..I'll just get one whatever i can get..