I haven't yanked the heads themselves yet. My choice is to not plan on it just being gaskets (
cracked heads* are not uncommon, I believe), and once these heads come off, they'll basically be just cores.
I talked to local shops, and an outfit in Texas, I think. CHI - Cylinder Heads International -
https://www.shop.headsonly.com/main.sc - Best to call them when looking for SC-specific heads, they were very helpful. When I called, they only had one ready, so unless that changes by the time I do the work, I expect to ship mine to them first.
CHI makes it as easy as possible, meaning they ship fresh heads to me and I return mine in the same boxes, all freight built into the transaction. Matter of couple days to receive. If they don't have a pair on hand, they send me boxes, I ship mine and they turn them around, no matter what work they need, in approx. one week. One price gets me fresh heads regardless of what it takes to make that happen, 12 month warranty.
Local shops didn't seem interested, wanting to inspect, then quote work, cost for crack fixes, etc., getting to them as they have time, etc. Quotes when I could get them were always slightly more than CHI - I was afraid of cost creep and being committed once they had my heads, which won't happen w/CHI.
* It's my opinion when you have symptoms on the car of overheating after running a while, with a not big bubble stream in the expansion tank that at least one head is cracked. Badly blown gaskets are more like when you see steam out the exhaust and the engine oil and coolant in the expansion tank turn into a milkshake. I don't have coolant in my oil, but like I said, I do have exhaust gases in the coolant, and same thing, it can run at normal temp if not stressed, but it always goes hot and bubbles (not big) if any load put on it or you just let it idle for 20 ~ 30 minutes, even when the fan works properly.
The tool is a test kit. The test fluid is sometimes separate. AZ's tool program works where you buy it, then use it, then return it and they refund. They didn't even charge me for the test fluid I went thru. The kit and fluid if you buy is around $30 ~ $40. Run the engine until you get a bubble stream, add the required amount of fluid to the tester, push the bottom of the tester into the fill hole on the expansion tank so it seals, and pump the bulb on the top. This will draw the air from out of the expansion tank up thru the fluid which will change color if exhaust gases are present. Took me a couple tries to get the hang of it, but not too difficult otherwise.
https://www.autozone.com/loan-a-tools/block-tester/oem-engine-block-tester/391378_0
https://www.autozone.com/test-scan-...st-kit/oem-block-tester-test-fluid/391381_0_0
If you have to buy them, I found both for sale on eBay, same items.