1973 Custom Classic 454 (Loss of Power) - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Your41Plague12 · 10-05-2011, 01:23 PM

No chance you have a 409. They have the oddly shaped heads like you said. Your 454 might be a different year, but it's definitely a BBC of some kind, not a 409. Just take one of your old plugs back there and see if they can get the part number for it. That will tell you a variety of engines it possibly could be.

savatreatabvr · 10-05-2011, 02:20 PM

So until I get the casting numbers off the back of the blocks it could be a 366, 396, 402, 427, 454 or 502? The casting numbers are easy enough to decipher I'm just having a hard time reaching them with my little telescopic mirror and flashlight! I think I need a brighter flashlight!

10-05-2011, 01:23 PM	#1
Your41Plague12 Registered User Join Date: Dec 2010 Location: Pittsburgh, PA Posts: 1,009	Re: 1973 Custom Classic 454 (Loss of Power) No chance you have a 409. They have the oddly shaped heads like you said. Your 454 might be a different year, but it's definitely a BBC of some kind, not a 409. Just take one of your old plugs back there and see if they can get the part number for it. That will tell you a variety of engines it possibly could be. __________________ Steve Member of the Foot Pedal Club '83 Chevy K20: 6" Rough Country, 3" Performance Accessories BL, Bushwacker Cutouts, 38x15.50 Mickey Thompson Baja Claws, 350 HP 350 crate engine from Jegs, Turbo 400

10-05-2011, 02:20 PM	#2
savatreatabvr Registered User Join Date: Oct 2011 Location: phoenix, az Posts: 508	Re: 1973 Custom Classic 454 (Loss of Power) So until I get the casting numbers off the back of the blocks it could be a 366, 396, 402, 427, 454 or 502? The casting numbers are easy enough to decipher I'm just having a hard time reaching them with my little telescopic mirror and flashlight! I think I need a brighter flashlight!



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