quick question before I run off to class which has been on my mind:

how to tell if the m103 block is at TDC? Does it matter which stroke the first piston is on? exhaust vs compression? or is TDC just when the first piston is at the top?

or am i supposed to look at the timing mark on the crankshaft pulley? what do I look for here?

cylinder head is easy enough I think, just the little hole behind cam sprocket has to line up with cast mark on the cylinder head?

John, there are several ways to find TDC.
TDC is generally referred to as the #1 piston being at TDC on the compression stroke, but of course there are 11 other times that one of the pistons is at TDC.
Depending on how accurate you need to be will determine the method.
Some quick and dirty ways are to pull the #1 spark plug and then just barely start the threads again, maybe just 1 turn. Then turn the engine over by hand only. When you hear air rushing out of the sparkplug hole, then you are coming up to TDC on the compression stroke. You can also stick a piece of paper towel in the hole and it will blow out as you rotate the engine to TDC.
If you have the distributor off, then you can look at the rotor, when it points to the #1 wire then you are approaching TDC at compression on #1. You can take out the other 5 plugs, and turn the engine over; when you get a strong resistance you know #1 is approaching TDC on the compression stroke.
After confirmation that you are on the compression stroke, then look on the balancer and find the stamped timing markings for 0 degrees. Slowly rotate the engine until the 0 mark is just below the little tab sticking down next to the crankshaft position sensor.

If you have the valve vover off, you can rotate the engine until the #1 intake valve (opposite the #1 intake manifold runner) opens, and then closes.
Then rotate the engine on up to the 0 mark on the balancer, or you can align the cam marks as you stated.

If you need to be really accurate, you need a piston stop to screw into the sparkplug hole, and a dial indicator wheel on the balancer. But that's a long story. Go to Compcams.com to read a 5 page tutorial on timing and engine.

DG

Thanks. I just needed to make sure the block and head are timed properly before I bolt down the cylinder head after a head gasket job. Someone decided to mess with the motor and turn the crankshaft pulley bolt, messing up my original TDC setup. Head was also sent off for some resurfacing and that put it out of TDC obvoiusly.

I'll just check the balancer for the 0 degree mark and double check the air coming out of the spark plug hole on compression stroke.

John,

Since you have the head off- look at the timing mark. Just make sure the piston is at the top of the cylinder... Set the camshaft at it's marking.

If you want to get the exact tdc point with head off- bolt down something accross #1 cylinder with a bolt or something preventing 360 degree rotation. Put the degree wheel on the crank, and a pointer on the block. Go one way, then the other. Half way inbetween is perfect tdc.

Follow the manual.

M

Yeah, if the head is off, that's a good time to confirm the zero timing mark on the damper is in proper alignment with the tab.
Just be sure when you line it all up that the #1 intake valve closes , then the distributor rotor points to #1. I put a small block Chevy in 180 degrees off one day, and was slightly embarassed when flames shot out during initial start.
But if all you're doing is bolting it back and getting the right teeth on the cam chain, then it's a pretty wide margin - if you are one tooth off, it's pretty obvious. The slight change in cam timing due to head milling is virtually insignificant in that case. You'll definitely know when it's right.

Oh, don't turn the engine backwards by hand, the chain guides and tensioner frown on that.

DG

maybe a silly question to ask, maybe not even relevant, but from where do I reference the timing mark? right before the tab bracket?

when I looked, i saw something like this

1|0 0|T

tab bracket was sitting a bit behind the T. is the TDC mark? what does the 1|0 signify? 10 degrees or 1?

distributor rotor was pointing at wire #1, so good news there.

started putting everything back together. hopefully it starts!