Holistic Engine Question

[Yale]

Hello. I'm staring down the barrel of a head gasket replacement on my 1980 270 (TL20B). I had a sudden loss in power on my way to work and a fresh new pinhole leak in my radiator along with coolant leaking from the head gasket. My question is in regard to cause. It seems like there was a spike in pressure (likely in the coolant system).

If I replace the head gasket, I don't want to immediately blow another one because I didn't take care of the root cause of the failure. 

Do these symptoms raise any red flags anyone? Water pump? Oil pump? There is a lot of buildup in the radiator, could some of that corrosion be stuck somewhere, causing pressure to build and burst at the seams?

Is there an engine that is a better swap? I love the truck, but sometimes it feels like I'm driving a lawn mower down the highway. 

I know just enough to be dangerous, so if anyone could advise, I would appreciate it. 

Edited July 16 by Yale
misprint

[SWFL]

When you remove the cylinder head, inspect it and the deck of the block. Look for pitting and use a machined straight edge and feeler gauges to check for anything warped. Often times overheating causes the aluminum head to warp and usually #2 &/or & 3 cylinder blows, from the reduced clamping force.

[Yale]

yep. I'm now in the market for a new head. 

[datzenmike]

The maximum cooling system pressure is set by the radiator cap. About 13 PSI, go above this and it vents.

 

A coolant leak at the radiator may have allowed the head to overheat and the head gasket blew.

 

The problem with overheating an aluminum head is it can warp, so replacing the gasket doesn't always solve the problem. Maximum warpage limit on an L head is 0.004" about the thickness of newspaper. Check with a professional flat edge and feeler gauges. A machine shop can trim it flat.

 

There should be minimum rust/corrosion in the cooling system if a good quality antifreeze is used. What you may be seeing is kettle scale build up. This is from using tap water that contains dissolved minerals in it. Over the years the radiator water boils away leaving the minerals. Always use distilled water to top up the radiator. I've had very good luck removing the radiator and laying it face down with the cap on and filling with CLR which dissolves the scale.

[Yale]

Where might I look to find a replacement head for this engine?

[Stoffregen Motorsports]

www.car-part.com