GrandeBoy92

I have a 96 Z28 with the T56 transmission. I had it taken a shop to have a block test done and they said it has a blown head gasket. This is my first LT1 and already causing a huge headache 😠 what is the best way to fix this issue? Have the heads surfaced, or used LT1? I don't have a lot of money. So most affordable option would be best.. Also before the car stopped going into gear all together it would pop out of gear into neutral while driving and the clutch pedal was soft. The shop said it's definitely the clutch but idk

Injuneer

How did they determine it is a "blown head gasket" - what is a "block test"? If true, the repair could be as simple as a new gasket, or as complicated as milling the head. You won't know until you pull the head. Did they tell you which head?

Have you checked the hydraulic fluid in the clutch master cylinder reservoir? Have you check the hydraulic system for leaks?

GrandeBoy92

They called it a block test and said something about exhaust fumes. Can't remember exactly what tho. I do remember him saying that it turned the dye yellow and it should be blue which told him blown head gasket. They weren't able to tell me which head either but how can I tell by pulling it? What's a good gasket to use? They checked the master cylinder and said it's full of fluid. How do u check the hydraulic system? This is my first LT1 and I honestly have no clue..

Injuneer

You could try a compression test or a leakdown test. That should identify the cylinder(s). Sounds like they were looking for combustion gasses in the coolant, which is a good way to check.

Once you figure which side the gasket leak is on, you have to remove the fuel rails, the intake manifold and the water pump. Then the head that was leaking. If you got lucky, only the gasket is damaged. But, depending on how long it was leaking, it could have eroded a groove in the soft aluminum head or spalled the surface. Or, the gasket may have failed because the head warped from overheating. You will only know what happened and how extensive the damage is when you remove the head. A professional evaluation of the head surface is recommended.

Probably best to try and find a new gasket with a compressed thickness that matches the stock gasket (0.049"), to maintain the compression ratio. Fel-Pro 1074 is the most commonly used, and reliable, but that is 0.039" compressed. OK in pairs. I think the Fel-Pro 9966PT is the stock compressed thickness.