Compression Stroke after verifying TDC

I added FITECH efi to my car and about ready to fire it for the first time. I just verified my balancer TDC mark and it's dead on.

My question is, how do I know if I am on the compression stroke? I set the piston stop and moved cw first, marked the balancer, then went ccw and marked. Then measured in between those two marks and it's right on "0" on the balancer.

I am working on a 340 with the timing marks on the driverside. My goal is to set the motor at 15* advanced, so it will fire quickly. The pic shows the two marks and the one in the middle is TDC zero.

Thanks for the help!