Head Gasket Surface

1991 CHEVROLET 1500

139,000 MILES • 5.7L • V8 • 4WD • AUTOMATIC

TBURDEN

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Can you tell me if this engine block is clean enough to install the gasket and cylinder head? I have cleaned it using a razor, WD40, brake cleaner, and a red/maroon type A scotch Brite pad. It appears smooth to the touch. There are some wear g else that needs to be done areas that the coolant made over the years. I am afraid to scrub with the scotch Brite any further as I do not want to damage the block. I cannot afford to take it to a machine shop, and it is still in the truck. The heads have been taken to the machine shop and are ready to go. Do you see anything else that needs to be done? Please help. This is my first time doing this and I do not want to make a big mess of it if I haven't already. This was my dad's truck, and I want to get it back on the road in his memory. Thank you in advance.

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Aug 5, 2025 at 5:09 AM

STEVE W.

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15,113 POSTS

The surface looks OK, but you are going to want to clean around the pistons VERY well because of the scotch brite and the debris from scraping. My usual process is to bring each piston up, then use brake clean or similar to flood the area around the piston, and use a feeler gauge or fine wire to clear out everything you can. The old carbon, dirt and tiny bits can act like sandpaper and score the cylinder walls. Another trick is to clean it real well, then push grease into the gap with the piston up, then as it goes down the grease will trap the dirt and crud in it. Wipe that out. If you can, it would be a good idea to pull the oil pan and use cleaner in the valley to flush the cam and lifters to be sure nothing is there as well. That is the one issue with doing an in frame, hard to keep things clean.

Aug 5, 2025 at 8:07 AM

TBURDEN

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Thanks Steve. Good advice. I will take all I can get.

Aug 5, 2025 at 5:03 PM

STEVE W.

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15,113 POSTS

You are welcome.

Aug 5, 2025 at 8:44 PM