Originally Posted by cadillac_al
I don't think I would tackle that job unless I actually see it leaking. It may not be the source of the overheating unless it is really clogged. I have never had a radiator clog on any vehicle in my lifetime except a small motorcycle radiator. I would do some further investigation. I would watch the temp gauge and see if it really goes above normal. Then I would test or replace the thermostat. If it still overheats with a good thermostat or no thermostat then I would try to see if the coolant is circulating. Usually I look in the fill hole but if I can't get my head in there or a mirror in there I might unhook a heater hose or something to try to see if it is circulating. It could be a bad water pump. good luck.
Based on my experience with the ‘91 we acquired in ‘18 - and the OP saying he’s overheating and leaking and needs to pull the radiator - he probably needs to pull it and have recored, power flush the block, replace all the rubber hoses (including the heater hoses and the elbow hose between the water pump and intake manifold), and thermostat.
And, since it’s easier to change the water pump with the radiator out, he could replace it while everything’s apart - but he needs to make sure to get the exact same water pump.
My experience was a consistent leak where the lower radiator hose connected to the radiator. It took me a few months to figure out the green patina above the hose port was sign of a leak.
Once I pulled the radiator - it was obvious that it had seen its better days.
I found a radiator shop that had been in business for 50+ years who said “better to recore than put in new”. He removed the end caps and put in a new 4 row slab (original was 3). There was plenty of clearance - GM apparently used the same radiator frame and end caps for their “standard” and “ extra capacity” radiators.