Pulled cover off my running well 50,000 mike 455 expecting to see a factory timing set. It is but with number one at TDC this is how chain and gears align. I would think the mark at top of cam gear would have been at the bottom and the word "front" would be upright at top.

 

If it ran well and the plug wire firing order is correct than you must be at tdc on the exhaust stroke.

 

You do realize that if you turn the crank one full rev, number one will again be at TDC, the cam mark will be at six o'clock and the word "FRONT" will be right side up, right?

 

I do.
Driver side front cylinder #1. Compression blows out plug hole as turning crank. At end of blow timing marks are as pictured. Continue turning one full rev and no blow from #1 as marks line up with "Front" right side up.

 

OK, so why are you concerned? With the marks at 12:00 - 12:00, number one is at TDC on compression stroke. With the marks at 6:00 - 12:00, number one is at TDC on exhaust.

 

No concern just curious. Seemed odd to have marks as 12 and 12.
Thanks for the input.

 

The rule of thumb is you set the dots at 12 and 6, but the ignition is actually firing #6 cylinder at that point. You have to turn the crank 1 full turn to 12 and 12 to install the distributor to fire on #1.

 

That timing gear looks good right now, but while your in there I would replace it. Eventually all the plastic will come off the top gear and end up in the oil pan and pick up.