I need to set timing on my 502..Just a question about how Im doing it. I know its suppose to be 8* btdc. My question is on my balancer I just have the one white line, no timing marks. And the timing index tab has the one big "v" which is 0* correct? Then it has 3 little "v" above that..each one of those little "v" should be 2 degrees right? So if I go by that its only at 6*?? Also another thing is how do I set it at 34* at 3000 rpm if I don't have all the timing marks on the balancer??

you need a timing lite that has adjustment knob or buttons,you line up the marks to 0 then read the amount of advancement on the timing lite.

Well right now..at idle, I have the light knob set at 0 and the white line on the damper is on the third "v". So to get it set a 34..rev the motor too 3000 rpm and set the knob at 34 and make sure the white line on the damper is in the big "v"?

Just confused..im use to having a damper with the marks on it and not just the one white line...

What ignition set up do have - any off this thunderbolt OEM stock Mercruiser IV or V or do have an aftermarket set up ?.

T-bolt V needs to be set into base timing mode first before setting / adjusting the timing.

T-bolt IV does not need to set into BTM.

Its a stock IV set up.

Is this a 22* advance set up?

3000 RPM is just approximate full advance. Rev the engine up slowly until it stops advancing. Then have your light set to 34* and turn the distributor until the marks line up. Tighten the distributor hold down bolt and recheck. It will probably move a little when you tighten it down. Take note of how many degrees it is off and readjust the distributor until it is at your desired timing when the bolt is tight. You may have to recheck and adjust a few times until you get it. Good luck.

When ya say make sure the marks line up...should the white line on the balancer be in the big "v" on the timing tab at 34*? Cause my balancer doesnt have the little tape on it that has the numbers on it..plus it sucks to see it down in the bilge..I have to lay my head down by the alternator..kinda scary with the belts right there...

Yes, line up the white line ("0") on the balancer with the large "V" on the timing tab. Whatever the adjustable timing light reads at that point is the timing.
Eddie