I'm putting in a new optispark and was wondering if I should hook
the vent tubing to the vacuum side for the bigger bottom one and the air intake for the smaller tube.
Or should I just vent it to the atmosphere.

I did a search but nothing came up for this.

 

the small goes to the intake the big one u can vent to atmosphere.

 

http://shbox.com/1/opti_vacuum_harness.jpg

 

Thanks
I'll hook it in before the s/c