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FLOutlander · 01-20-2007, 06:36 PM

OK, I did some more research today while tinkering with the truck. First off, I took off the drivers' side valve cover to take a peek at the head casting number. Came up with 3988998 and a date stamp of E 7 75. So it was cast on May 7th, 1975. I looked up the casting number and can't find a match, so I don't know any more than I did yesterday. I can't see the engine block casting number untill I get the engine out of the truck....not sure when I can do that, though.

Second, I looked over the RPO Codes list in the truck. For the rear end it says "GQ1 Rear Axle Standard" Went online and looked over many RPO Code Lists and came up with "Rear Axle-Standard". So I STILL don't know what ratio I have back there. There is no stamp or tag on the rear end. All I know is that it's a 10 bolt. But I don't know what spline or what gear ratio...or the diameter of the gear set. I guess that'll have to wait till I can pull all that apart.

01-20-2007, 06:36 PM	#17
FLOutlander Registered User Join Date: Jan 2007 Location: Tallahassee, Florida Posts: 21	Re: My Project Truck OK, I did some more research today while tinkering with the truck. First off, I took off the drivers' side valve cover to take a peek at the head casting number. Came up with 3988998 and a date stamp of E 7 75. So it was cast on May 7th, 1975. I looked up the casting number and can't find a match, so I don't know any more than I did yesterday. I can't see the engine block casting number untill I get the engine out of the truck....not sure when I can do that, though. Second, I looked over the RPO Codes list in the truck. For the rear end it says "GQ1 Rear Axle Standard" Went online and looked over many RPO Code Lists and came up with "Rear Axle-Standard". So I STILL don't know what ratio I have back there. There is no stamp or tag on the rear end. All I know is that it's a 10 bolt. But I don't know what spline or what gear ratio...or the diameter of the gear set. I guess that'll have to wait till I can pull all that apart.