How much slack should a timing chain have ?

Do you have a dial back timing light?

 

Look again at the linked chart, at the part number. It is a points distributor. Std. mean points. They offered both in 1974. Do you have a dial back timing light.

 

Something is very wrong then. If the 30* mark is under the water pump pulley or further, the timing is very far advanced. What happens when you turn the distributor clock wise? Can you get the 30* mark back to the timing tab, or does the engine refuse to run like that?

 

If you are absolutely sure that that your balancer hasn't slipped, and that you correctly marked a 30* line, then the only time I have seen this happen is when there is a vacuum leak into the lifter valley from an intake manifold that isn't fitting right. That can happen if the block/heads were milled enough to affect port alignment. This is a mystery engine, and there is no telling it's history.

 

Tim,
You have to be mistaken. That makes absolutely no sense to me. If the 30* mark is under the water pump pulley, you have about 60* of timing. What your telling me is that changing springs changes you timing by 50* No way that happens.

 

I don't know what to tell you then. Like I said, that makes no sense to me at all. Springs and a bushing don't make that kind of a difference.

 

Even if the springs are too weak, there is only a maximum of 28* of timing in that distributor.

 

That is what I thought. I would check the balancer for slip by using a piston stop. If you have enough travel by turning the distributor to get the mark onto the timing tab, the distributor is installed correctly.

 

You can make a piston stop from an old sparkplug. Knock out the porcelin. Then thread the inside of the plug with a 3/8 tap. Then use a 3 1/2-4" bolt and screw it in to the plug shell. Then put the stop into the #1 cylinder. Use a breaker bar to slowly turn the crank clockwise until the piston contacts the stop. Make a mark on the balancer at the 0 on the timing tab. Then turn the crank counter clockwise until you contact the piston again. Make another mark on the balancer at the 0 on the timing tab. True TDC is exactly halfway between your 2 marks.