487 vs. 487X heads - The 1947 - Present Chevrolet & GMC Truck Message Board Network

brennecke · 06-10-2002, 10:16 AM

I scored a set of 487X heads for nothing (found 'em in the dirt near a guys workshop, asked and they are mine). I had them magnafluxed, and they aren't cracked. My truck currently has 487s on. My question is whats the diference between the two sets? I was told origionally that the X meant big valves, but I measured, and they are 1.94, 1.5. Somebody else said that the X heads were meatier and could be ported more. From what I can see, they may need porting, but there's no need to do any port matching. The intakes are huge, and the exhaust ports are as big as can be without being bigger than the gaskets.

Any clue?

06-10-2002, 10:16 AM	#1
brennecke Registered User Join Date: Apr 2000 Location: Missouri Posts: 469	487 vs. 487X heads I scored a set of 487X heads for nothing (found 'em in the dirt near a guys workshop, asked and they are mine). I had them magnafluxed, and they aren't cracked. My truck currently has 487s on. My question is whats the diference between the two sets? I was told origionally that the X meant big valves, but I measured, and they are 1.94, 1.5. Somebody else said that the X heads were meatier and could be ported more. From what I can see, they may need porting, but there's no need to do any port matching. The intakes are huge, and the exhaust ports are as big as can be without being bigger than the gaskets. Any clue? __________________ Never tire of doing what is right II Thess. 3:13 Northeast Missouri 71 LWB original 350 3/speed Soon to be 500



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