I can’t speak for l98 powered Vettes, but if you have an lt1 car and are still running an original cooling system it’s definitely worth considering replacing if your car struggles with temps even a little. I’ve flushed the system in my 94 several times, and while it helped, it still tended to creep up to 220-230 in stop and go traffic on hot days. Like many, I’ve read all the cooling threads and convinced myself it was just normal. “Normal” or not, I decided a refreshed cooling system certainly can’t hurt on a 25 year old car with 110k miles.
I replaced the radiator, surge tank( the black upper tank by the passenger side windshield), and upper and lower radiator hoses. Nothing fancy on the radiator, just a stock replacement from amazon. I got it all buttoned up this afternoon and after refilling and burping the system, it happily idled in my driveway for a good 30-40 minutes and maintained btw 190-195 no problem. It did hit 212 once, and the number one cooling fan kicked on and quickly brought it back down to 190 range and stayed there. It never even got hot enough for the secondary fan to come on which is at about 230. Before, under the same conditions it would have hit 230, kicked on the second fan, and then stayed around 215-220 until I got it moving on the road. I’m very happy to see what a difference a fresh radiator makes on this thing, and it will be nice not to feel like I have to watch the coolant temps like a hawk all summer.

 

I just replaced the original radiator on my 85 and the highest temp so far is 201 at a stop, so I can attest the same for the l98. Also nothing fancy, spent about $140.

 

Yep, for all the talk about these cars running hot, it seems perfectly happy to maintain very reasonable temps with nothing more than a fresh stock replacement system.