ok i think my #1 cylinders at tdc ( i didnt set it, its remanufactured and that the way i got it, the guy said it was "set up ready to go" ) i can see the top of the cylinder i think from the spark plug hole. If my #1 piston is at top dead center would my #6 cylinder also be up near the spark plug. because i can only see the cylinder from the spark plug holes in the #1 and #6 the rest are lower and out of sight.

#1 & #6 will always be at the same position in the hole, look at the firing order of a chevy engine.

1 8 4 3 6 5 7 2

Since 4 stroke engine require the crank to make 2 complete revolutions for every firing cycle(the top end rotates at 1/2 the speed of the bottom), the 2 opposite cylinders will always be in the same position.

Unless of course, you spin the engine to 12,000rpm & bust the crank into pieces & then the pistons will be out of sequence & possibly in different zip codes. :eek: :eek: :eek:

If your really worried about it and want to check it i used to get an old metal hanger, i know those are getting really hard to find now a days but i cut it about 6 inches and bend it just right to stick it in the #1 cylinder and turn the motor over with a rachet till the hanger stoped moving up. You can turn it more and then notice it on its way down. You just have to bend it rite and it works fine, i think i still have it somewere in my toolbox.

Yes, 1 and 6 hit TDC at the same time.

The difference is in the valves/cam. When #1 is at TDC of the compression stroke #6 is at TDC of the exhaust stroke and vice versa.

The #1 piston needs to be at tdc on the compression stroke to set the distributor. If you are uncertain, pull the(drivers side) valve cover and see if the intake and exhaust valves on #1 are both closed (both up). good luck.