Bad head gasket? I

[tino0217]

I have a 71 C10 with a 350 small block that was put in by the previous owner the engine is between 74 and 78 I recently put on new timing chain carburetor radiator spark plugs spark plug wires and I've noticed timing was perfect for about a week and then I noticed when I get up to about 60 miles per hour I can see the tachometer bouncing around. Had a friend come and look at it and he noticed that water was trickling out of the tailpipe on the passenger side when i shut it off. There's no back firing. He said it was probably a blown head gasket there is no water in the oil when I pull the dipstick. I replace the intake manifold gasket new manifold gaskets new water pump new fuel pump new alternator new starter to keep this as a daily driver should I consider putting in some Blue Devil?

[yuccales]

Are you loosing coolant? Could the water out the tailpipe be condensation?

[tino0217]

Loosing coolant off and on but not, sometimes i need to add 16 oz som nothing. I've found all vaccum leaks. I know about condensation but my friend showed me the water that trickles out after i shut it of

[Grumpy old man]

If you suspect a bad head gasket look for oil in the water , water in the oil , bubbles coming from radiator and pull the spark plugs and assess the color a white or steam cleaned looking plug while the others are tan color is a good indicator of a bad head gasket .

[tino0217]

My number 4 plug I have to clean it every few weeks because it gets oil deposits on it the others look fine

[Grumpy old man]

if you make short drives I'd suspect condensation If after a long drive and you still see "water" dripping from exhaust I'd start digging further , Do you have a coolant recovery tank ? or are you constantly topping off the radiator ?

[Sheepdip]

Use one of these and remove all doubt. You local Auto Zone etc. should have one to rent unless you got a buddy with one.

https://www.amazon.com/JIFETOR-Radia...922647&sr=8-14

[BigBird05]

Have you done a simple compression test yet?

[RustyPile]

If you don't have a coolant recovery system, it's not unusual to occasionally add small amounts of coolant to the radiator.. As Grumpy old man said, check for water in the oil and oil in the water.. Beg, borrow, or steal a cooling system pressure tester.. Be sure the cooling system is completely full and remove all spark plugs.. Pump up the cooling system to about 15 - 18 lbs.. Let set for several minutes, then spin the engine over on the starter.. If coolant is leaking into any cylinders via a crack or blown gasket, coolant will spray out through the spark plug holes..