GME12

Engine is a 2007 Mercruiser MPI Horizon MIE. I recently installed a new 383 long block and need to verifiy the timing is adjusted properly. The engine builder installed the distributor with #1 cylinder at TDC. And marked the harmonic balancer at TDC. I read the timing procedure in the Mercruiser #24 Manual Supplement and just purchased the Diacom software needed to check this. What I don’t understand is how is the timing light going to confirm the timing is at 8* BTDC when there is no timing tab on the engine? The other engine doesn't have one either so apparently they did not come from the factory with them.

I haven’t had a chance to use the software yet, so if someone can step me through this, I would appreciate it.