I have a Blazer and use the Thule wide ski rack with the special feet exactly made to fit the Blazer luggage rack length wise bars. I have used it for over 10 years no and iyts still good. Do get the lock with a key version. The ski racks hold the rods better than a rod rack IMO.
The blazer will actually fit a rod about 10 feet 10 inches long if you put it kitty corner and bend the tip along the windhield.
When I built my Century Canal rod I put the uncut rod in the truck diagonal , flexed it a little along the windshield interior and made a mark then cut it there. No specific feet and inches , just the longest I could get in my Blazer.