I'm restoring a bike with almost complete 7402 Dura Ace components. Except the chainrings are a rather ugly set of salsa 53/39 rings. I'm looking to get the correct chainrings, or at least ones that look correct.

Is there any difference between Dura Ace 74XX rings and 600 64XX rings? I wouldn't mind saving a little money.

As a follow up, how about between 74XX/64XX and 77XX/67XX rings?

I think the 7700 rings were lighter, and uglier, than the corresponding 65xx rings.
67xx rings are 10-sp.

I always thought 6400 rings were just not as polished as the 7400 rings, other than that, no difference..

Judging by Part number, you're dealing with 8 speed and early 9 speed chain rings. Not too much difference other than finish and slightly lighter weight. I would stick with 'like' part #'s... don't mix a 74xx D/A chain ring with a 77xx; they won't mix very well. Same with 64XX vs. 65/66xx... you get the picture.

The x400 chainrings won't be ramped and pinned and could very well be biopace. That being said, I've put newer ramped and pinned large rings (all you need on a double, no need for ramps nor pins on the smaller ring) on older cranksets in the past with amazingly positive results in front shifting.

I'm currently running a 6600 large ring and a superbe pro 38t ring on my 9 speed (6510) race bike. Shifts great.

I was thinking there might have been an issue chain wise between 64xx and 65/66xx; you know, a 9 speed chain with
an 8s/9s chain ring mix. Sounds like there isn't an issue after all... cool!