Thinking about doing a manual seat conversion in my 89 IROC. Is the weight savings and time worth it? Also, is it pretty straight forward? Looking on eBay the manual rails can be had ~$40. Search came up with nada, that's why I'm asking.

I assume it's a power seat track you're considering replacing?
What is the over-all performance goal sought?

For $40, you'll save at most 3-7 lb's. That's ~ .01 % of the vehicle
curb weight. And you won't be able to notice any performance improvement.

It's going to be street/drag. Right now it's at full weight minus the spare, 3515 with a 1/4 tank of gas and the LS1. I'm just going by the everything adds up philosophy. 5 pounds here, 15 there eventually you're losing 100 lbs. The hood is the next thing gone, and the battery to the trunk.