240Z Flywheel bolt under head length size

[Marvo]

I am converting my standard 240Z from Auto to Manual transmission and I note there is a difference in length of the manual flywheel bolts, they are supposedly longer than the ones fitted on an Auto from what people talk about.

The Parts Catalogue shows 12315-U6000 for manual and 12315-A4000 (25.5mm length) for the Auto set up. My question is what is the under head length of the manual bolts? The ones off the car (Auto) are 25mm which when slaved thru the new flywheel leaves around 12mm of threads for the crank boss which seems a bit skinny hence I assume the need for longer bolts.

Any advice appreciated.

 

[atomman]

You will need longer bolts and also a spigot for the end of the crank as the autos don't have them fitted

 

[jonbills]

These should be good: https://www.ebay.co.uk/itm/324764355352

 

[Marvo]

You will need longer bolts and also a spigot for the end of the crank as the autos don't have them fitted

Crank spigot I have thanks

 

[Marvo]

These should be good: https://www.ebay.co.uk/itm/324764355352

Thanks look good but am trying to get Nissan ones ideally, I think I have found some on Z car depot in the USA. It looks like the correct length is only 2mm longer than the Auto ones ie 27mm versus 25mm.

 

[uk66fastback]

Can’t go wrong with ARP bolts in my experience …

 

[Marvo]

Finally got to the bottom of this which may be of help to someone, the difference between the auto UHL and manual UHL bolts is just 2mm and at a thread pitch of 1.25mm this equates to around not much! The UHL of a manual bolt is 27mm and an auto bolt is 25.5mm. I suspect this makes them interchangeable effectively, and of course you would have to measure the thickness of the particular flywheel you were fitting to make sure anyway. Hope this helps and thanks for all the responses.