300zx na-t diff

[Azazel703]

I have a 1990 300zx na that I swapped with a tt engine and I need to know what year q45 diff I need

[NolimitZ32]

You don't need a Q45 diff, your NA diff will work just fine unless you are specifically looking for the lower gearing. As for the years, you'll need to search, It's been covered at least a couple times and I don't know the answer.

[itsa300zx]

I have a 1990 300zx na that I swapped with a tt engine and I need to know what year q45 diff I need

97-01 FGY33 will swap over with small change over of the input flange.

As no limit stated, not needed unless you are pushing lots of power, ie over 450-500 RWHP.

I'm at 430whp and 450 tq for the past 3 years it's been holding fine.

[DCaff300ZX]

The only reason to change the diff would be failure of your diff, or as mentioned wanting a different ratio for track vs. drag racing or some other special need. Even then a swap of the correct Z32 diff should accomplish that. The NA with AT has a different ratio than M/T NA's, and the TT's are handled the same by Nissan so there are basically 4 ratios to choose from, and all the with same LS diff/diff capabilities as anything else Nissan. I know the TT M/T ratio is 3.69 and NA A/T is 4.11 or 4.10, and while the others (NA-M/T and TT-A/T) have some other ratio used between these two given ratios. A quick search of Nissan LSD's should net those other two ratio numbers.
Furthermore, an experienced mechanic can easily swap the ring gears from one to another should the owner have need for several (track racing) different ratios.

[itsa300zx]

The only reason to change the diff would be failure of your diff, or as mentioned wanting a different ratio for track vs. drag racing or some other special need. Even then a swap of the correct Z32 diff should accomplish that. The NA with AT has a different ratio than M/T NA's, and the TT's are handled the same by Nissan so there are basically 4 ratios to choose from, and all the with same LS diff/diff capabilities as anything else Nissan. I know the TT M/T ratio is 3.69 and NA A/T is 4.11 or 4.10, and while the others (NA-M/T and TT-A/T) have some other ratio used between these two given ratios. A quick search of Nissan LSD's should net those other two ratio numbers.
Furthermore, an experienced mechanic can easily swap the ring gears from one to another should the owner have need for several (track racing) different ratios.

FYI,
There are only two versions of diff in the z32 r230 TT with 3.69 gearing and the r200 NA with 4.09 gearing; does not matter if MT or auto. You can not just swap the r230 with the r200; a full rear sub frame swap must be also done. The q45 diff is a r200 with a 3.?? Gearing and is a direct swap minus the companion flange.

[NolimitZ32]

^ this is correct info as far as I can recollect. I know for a fact that the Z32 only had 2 options for the the diff TT and NA

[DCaff300ZX]

^ this is correct info as far as I can recollect. I know for a fact that the Z32 only had 2 options for the the diff TT and NA

Hmmm, coulda swore there were 4...anyway, seems like we have this covered no matter which way the OP wants to go.
Note: Just checked the fsm and yes, only two ring gear ratios (4.08 and 3.69) available...not sure where I got the rest.
Carry on!