Top Dead Center Timing Mark?
 

I recently replaced my distributor drive gear on my 98 Blazer LT and following research on correct timing mark alignment for top dead center, noticed I had only one groove in my harmonic balancer. I am having difficulty getting it to run now. All research tells me there should be two marks and only the second(90 degrees apart from first) should align with the top indicator on the front cover tab. Can anyone tell me if having only one groove in the balancer is commonplace and if so, which of the two indicator tabs do I use to align with?

Recently I had to find top dead center on my 1996 Blazer LS. I used the diagram from here: http://www.justanswer.com/chevy/4kr8...ec-engine.html

My Blazer exactly matched the diagram with 2 slots on the harmonic balancer separated by 90 degrees. If one slot is at 1 o'clock, the other should be at 4 o'clock (relatively). Per the diagram, the one at 1 o'clock needs to align with the "V" tab located at about 1:30 o'clock on the timing cover. Since you say you only have one slot on the harmonic balancer, I cannot tell if it is the one at 1 o'clock or the one at 4 o'clock. Your wording hints that you aligned the "second one", which I take to be 90 degrees clockwise from the first, with the "V" tab. That would not be correct based on the diagram for the '96 Blazer. I realize the '98 may have a different alignment diagram than the '96.

Thanks for your reply. No, I doubt the year makes a difference and from what I hear, all of these should have the two marks on the balancer. I have one only 1. I am going to have to try something else as I have failed several times in the effort. I saw a good method of determining tdc on You Tube here: