Doing a 350 tpi swap. The wiring harness that came with the motor did not have a connector for the coil so i have to figure out where the wires from the grey connector on the gm dual connector coil go.

From my stock wiring harness the large pink wire attached to the connector leads to my fuse block and has 12v when the key is turned on, the smaller wire (white) lights up when i put the test light to ground. I am not 100% sure where this white wire goes. The black connector leads to the distributor and i'm not worried about that one.

Don't hate me for this but the engine is going into an 87 chevy k5 blazer which was previously tbi.

 

Chevy power site said the white wire on the gray connector can be wired to a tach.

Problem i'm experiencing is that I can't get spark.

 

Yes, the white wire goes to the tachometer in your dash.

If you don't have spark, I'd disconnect the timing set connector (I believe tan/black wire) first. If you still don't have a spark, I'd check the distributor ignition module for power.

Hope this helps.
Lou