I blew a head gasket on my 84 not long after getting it. I did the gasket, water pump and T chain, using all toyota gasket. I should have done the oil pump and front main seal while I was at it, I ended up having do that some years later. The truck has been my daily driver for 11-12? Years.
The aftermarket 22r fuel pumps are not very reliable. I've had a couple leak oil from the hole on the bottom and one that started leaking fuel. I Finally bought a toyota pump.
I wouldnt buy anything until you know for sure that you have a bad head gasket.
Here is another way to test for a leak between the cylinders and the cooling system
https://www.napaonline.com/en/p/BK_7001006
