240z FS5W71C swap using FS5C71B Bell Housing

[Tebirkesueth]

Hello all, 

I'm pondering doing a gearbox upgrade as I have everything out of the car for my restomod and my 5-speed gearbox is "missing" 5th gear. The car is a 73 240z Europe edition and I believe I have the FS5C71B gearbox mounted in the car. Searching around I found recommendations of the FS5W71C swap from the 180SX, 200SX, and 240SX. I can find plenty of rather low mileage FS5W71C gearboxes for sale so that is not a problem.

I read the following guide http://zhome.com/ZCMnL/tech/240SX5spd/transmission.htm and it is highlighted that you need the FS5W71B bell housing. 

Question is -> Has anyone had any experience using the FS5C71B bell housing for this swap rather than the FS5W71B? 

Cheers,

Erik

[NewZed]

The FS5W71B does not really use a "bell housing'.  It's a combined bell housing and front gear case.  If your FS5C71B uses a separate bell housing like the FS5C71A then it won't work.  I could only find a picture of the A model, not the B model, in the 1972 FSM.  The W and the C designate the type of synchro system I believe, so if the B designates the case style you might be able to use it.

But.  That FS5C71B might be worth more to a restorer.  You could probably trade it for a worn out transmission that will work better.  There are small issues with the early cases, like the reverse switch location (mentioned in that ZHome writeup, I think), that can be avoided with a later model case.

The A transmissions are three piece, and the B's are two piece.  Steel plates separate the aluminum pieces.

 

Edited October 29, 2017 by NewZed

[Tebirkesueth]

Thanks for the input NewZed,

the FS5C71B has a combined bell housing and front gear case as well (courtesy JDM junkies). I have to confess that I'm not 100% certain I have an FS5C71B gearbox, but it makes the most sense as my car is the right year and market to have one...The value of a restored original gearbox is a good point. I actually have two gearboxes with the same housing (at very similar).. so I plan to keep one original and restore it for future use.   

After looking around in my picture archive this is the best comparison I can find in terms of the housings;

FS5W71B housing from http://zhome.com/ZCMnL/tech/240SX5spd/transmission3.htm

My gearbox as taken out of the car... looks promising at least. I might pick-up the FS5W71C gearbox anyway as I can get my hands on it quite cheap. 

Thanks for the input!