I've got the timing cover off my 06 3.6 CTS in the next town, and before I go back out there, I'd like to know how to check the current timing. Symptoms imply the timing chain(*) have jumped a tooth.
Searches for 'LY7 Timing*' always return data on timing marks aligning the cam gears and CHAIN, which is only useful for installing a new chain. For simply verifying timing with the current chain, I need the marks aligning cam gears and BLOCK.
Does anybody have any info on or pics of the proper cam positions at TDC?
I could post in the Cadillac section, but the LY7 was in so many different GM models, I thought I'd have better luck here.

Cams are not aligned to the block or the chain, they are aligned to the crankshaft by means of alignment marks.

Right. Where are those alignment marks? All the timing marks I can find online are for chain installation, which show where to put the 'yellow' links.
for example:
http://www.cadillacforums.com/forums...d-fully-6.html
I count 4 marks on each cam in those photos, a little circle with an 'L', and a triangle with an arrow. In the pics, the drivers bank seems to align the 'L'/circle marks with the bright links, and the passenger bank seems to use the arrow/triangle marks. All these marks are pointed in all directions, to match the chain'* bright links.

Where are the 'alignment marks', that tie to the crank position? On other cars I've worked on there is an arrow that points up when the crank is at TDC; I don't see anything like that on these cam gears.