Timing

So whats the problem? Line up the gears dot to dot.

I got the timing gears lined up, bottom crankshaft mark (dot) pointing at 12 o'clock and the camshaft gear mark (dot) pointing at 6 o'clock, # 1 cylinder is at TDC but when I check it is not on the compression stroke shouldn't the #1cylinder be on the compression stroke?

Yes it should be on the compression stroke

What size engine is this?

Ok so I need to take the chain off and rotate the camshaft gear until the intake and exhaust valves on the #1cylinder are closed and the mark (dot) on the gear is pointing at 6 o'clock aligning with the mark (dot) on the crankshaft

5.7

The engine gets to the compression stroke when the dots come around and line back up. Crankshaft turns 2 revolutions per 1 revolution of the camshaft gear.

Yes, 6 o-clock on the cam gear, 12 o-clock on the crankshaft gear.

Ok so what your saying is I do not need to take the chain off and rotate the camshaft just turn the engine over time the marks line up and my #1 cylinder is at TDC of. The compression stroke

Correct. Rotate the crankshaft over twice and the timing marks will line back up and it will be on the compression stroke. It is good to do this to verify that the gears are in the correct position, so to see that your not off a tooth or two.

Ok understood but I tried to do just that and when I turned the engine over to bring the #1cylinder to TDC on the compression stroke the marks did not line up the crankshaft mark was pointing 12 o'clock and the camshaft was pointing to 12 o'clock as well. Maybe I need to turn the engine a few more times.

For that point 12 to 12 o-clock just one more rotation of the crankshaft. The marks should line back up and you will be on the compression stroke.

The number 1 cylinder on a Chevy is driver's side front cylinder. Are you using the correct cylinder?

Oh god I hope so,

Yes lol

Did the marks line back up? You can't leave me hanging here...lol

Yes they lined up perfectly

But like I said when I checked the #1cylinder it was TDC but not on the compression stroke

So where do you feel the compression stroke, when the camshaft gear timing mark is at 6 o-clock or at 12 o-clock position. No matter what the crankshaft gear would be on zero, TDC. It may be the compression stoke for GMC at the 12-o-clock position.

When the camshaft points 12 o'clock along with the crankshaft

Then that is it. That is when the rotor would point to the #1 spark plug tower on the distributor cap.

This is what Im trying to find out, I need to install the distributor so all I need to do is to make sure the #1cylinder is on TDC of. The compression stroke

I thank you for you help I'm going to reassembled the timing chain cover and the distributor and give it a go!

Your engine timing is right on now and the rotor point to number one distributor contact inside the distributor cap on the compression stroke. Now depending on what distributor cap is on there, say if the towers are in a horizontal position, #1 contact is at like the 8 o-clock position and that is where the rotor would need to point. If the distributor cap has vertical towers then the rotor just points to the #1 distributor cap tower. On the low profile distributor caps, the spark plug towers are in a horizontal position, #1 tower is still at like 5 0-clock but its contact under the cap is at like 8 o-clock.

Very good thank you!!I will get back with the results

Well it is now morning, so good morning to you Jim!

Rowefast just wanted to let you know that my truck is purring like a kitten, thanks for you help

Far out! Glad it is fixed. Happy trails...

Rowefast have you ever swamped out a rear end with drums for one with disk breaks on a gmc k1500 if so what do you recommend

I have not done this, but seen it done after they had it all done. At the time I didn't think to ask about any details.