Vacuum modulator line question??

[newmaac]

I am installing a TH350 in a 69 C-10 longbed with a 350 engine.
The truck originally had a 3 on the tree.

I don't have a modulator line for this transmission.
I assume that originally there was a pre-bent line, with rubber hose on the ends to attach to the manifold and modulator???

1. Am I correct in that assumption?
2. Can I simply run a length of 5/16" vacuum line to make this connection? With the modulator facing towards the rear, it seems like I would have to have a fair amount of slack in the line, in order not to kink it.
3. anyone have a spare line or a suggestion for a good source?

TIA,
Mike