1978 Dura Ace bottom bracket width

I'm trying to work out the bottom bracket width that I need for my build, but it's giving me a massive headache. I can't find any information on my specific cranks after looking for an hour or so, the closest I found was this (1973 Dura Ace EX catalogue)
http://www.sheldonbrown.com/shimano1973/pages/da6.html

My cranks are Dura Ace EX (1978), they are double road cranks. I calculated my sprocket to have a chainline of 43mm.

If anyone could help that would be ace.

According to Velobase (http://www.velobase.com/ViewSingleComponent.aspx?ID=33E0D8C7-7DD4-44BE-9258-82D777192E93&Enum=115&AbsPos=22) the lengths were 112mm English thread and 113mm Italian.

Surely from that you can work out what length spindle you'd need to run a single chainring on the outside of the spider arm (assuming you want it for SS/FG use).

http://www.sheldonbrown.com/bbsize.html#shimano

Scroll down till you see Dura-Ace 7200 (the alternate designation for earliest DA EX)

BB needs to be 112mm for 68mm shell, and 113mm for Italian.

These will give you a 43.5mm chainline (mid-point of the two rings at 41mm and 46mm) if you want the outer ring to be at 43mm, then you will need a bottom bracket that is 6mm shorter i.e. 106mm

The shortest Shimano I recall seeing are 107mm.

Not that hard mate!

Sam you beat me... + Velobase is the DON.

Thanks for the help guys, I'll try and find a 106mm bb but will probably end up with a 107mm.

You want to use it for singlespeed?
ediT - buy the UN54 107mm - it will be fine.

Fixed

yeah yeah, same difference.
Sheldon is hard. I knew that page was there and still had to do 3 searches to get the right results.
As for velobase.. if you use older parts it is FTW.

Thanks a lot, I looked on sheldon loads but couldn't work it out. Bookmarked velobase now I'd never heard of it but it looks like a really good resource. Cheers

Gt site. Thanks
(http://www.velobase.com/ViewSingleCo...=115&AbsPos=22)