Tricross Drivetrain Changes - Will I explode?

So I'm buying a Tricross Single cross off here and I'm picking it up tomorrow.

From what I've seen from Specialized's archives is that is came with 68 x 103 square taper bottom bracket and some Sugino OEM cranks.

I've found some Dura Ace cranks in the parts bin; they're octolink so mid to late 90's I guess but unsure of the series. But I don't have the BB. So I'll need to buy a BB. The narrowest that I can find is 68 x 113. So do you guys think it will work? I'm concerned about the chain line primarily. The rear spacing is 120 and I'll have a single speed freewheel out the back.

The guy that built it had rotor cranks and external cupped BB but he had re-spaced a 130mm rear hub and used a single sprocket and spacers so he could adjust the chain line easily.

So will I and the bike explode or will it work so beautifully that I and the bike will undergo metamorphosis and become pure light and energy?

Thanks oh wise ones.

I reckon you'll want this BB
http://www.wiggle.co.uk/shimano-105-5500-octalink-bottom-bracket-1/?lang=en&curr=GBP&dest=1&sku=6572&kpid=6572&utm_source=google&utm_term&utm_campaign=UK_PLA_Components&utm_medium=base&utm_content=mckv%7csy76aWlwL_dc%7cmcrid%7c67090789502%7cmkw%7c%7cmmt%7c%7cmrd%7c6572uk%7cmslid%7c%7c&mkwid=sy76aWlwL_dc&pcrid=67090789502&prd=6572uk&pgrid=17507338502&ptaid=aud-131695477502:pla-128000857982

Sweet, thanks @jogger. So 6mm will be tolerable? Could I use a multi speed chain to ease the potential chain line stress?

Not sure where you're getting 6mm from?
I'd just get that BB, install with chainset and see what its like.
Pretty sure it will work.
Just use 1 speed chain.

Are the Dura Ace cranks road double or track?

If track, they'll give a 42mm chainline with the correct BB.

If road, the chainline of the outer ring position will be 46mm. So you'll want a BB that's 8mm shorter/narrower than the recommended one. Given the limited options for Octalink, you might have to make some compromises, or sack it off altogether.

Look on the back of the cranks for the model number.

@Scilly.Suffolk they're road double, or at least they should be. I'll check the numbers later.

Edit: They're FC 7700

Narrower bb and chainring on outer position will be the nicest aesthetically and in terms of Q factor but you could also run the ring on the inside with or without a chainguard on the outer position.

CRC have Octalink BBs as cheap as £13 if money is an issue, just not got the narrower ones in that cheap model.

you could also run the ring on the inside with or without a chainguard on the outer position

If I was being sly, I'd claim that covered that under "some compromises".

But I didn't, I forgot.

@Lanterne_Rouge

With the recommended BB, the chainline of the inner ring will be 41mm, which is fine.