Help Identifying a tag - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**wcstory** · 07-04-2015, 08:40 AM

I've been working on my 1966 GMC 305E that has some bent push rods due to stuck valves - that's a different thread.

During the top end tear down I found a metal tag wired to the exhaust bolt keeper it reads "060" or "090". The truck has under 13,000 miles on the odometer and came from a low use municipal setting.

Any ideas?

1963c-10 · 07-07-2015, 11:05 AM

I was thinking maybe engines been rebuilt and was bored .060

**TJ's Chevy** · 07-07-2015, 09:23 PM

No .060 over pistons available that I know of for a 305.

**wcstory** · 07-07-2015, 09:39 PM

I agree on doubting a rebuild. Everything I found from head gaskets to valves was stamped GMC.

I was wondering about a special order tag. Being a fire support truck, it has double belt pulleys, dual batteries, etc.

One thing is clear it was "build or unit 2591" there are grease pencil marks throughout the truck

1963c-10 · 07-08-2015, 01:32 PM

Quote:

Originally Posted by TJ's Chevy

No .060 over pistons available that I know of for a 305.

Egge shows .060 piston rings in stock for the 305 GMC V6.....so someone either did or still does make them. Your far more a GMC V6 guy than me though TJ. I don't even know how far a 305 can be over bored personally....but as thick as the walls are I would imagine you'd have room.

Odd tag either way...and the mystery continues.

**wcstory** · 07-08-2015, 01:40 PM

I had meant to mic the bore, but it slipped my mind. Heads are back on now.
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1963c-10 · 07-08-2015, 01:54 PM

Did it look like an recent work had been done when you had the heads off?

**wcstory** · 07-08-2015, 02:03 PM

Everything I saw looked original. Head gaskets stamped "GMC", valves stamped "GMC", etc.... There was none of that damn silicone gasket material everyone loves. The head and deck surfaces had no swirl or scrape marks (till I started)
Posted via Mobile Device

07-04-2015, 08:40 AM	#1
wcstory Registered User Join Date: Jun 2006 Location: Cape Cod, Ma. Posts: 236	Help Identifying a tag I've been working on my 1966 GMC 305E that has some bent push rods due to stuck valves - that's a different thread. During the top end tear down I found a metal tag wired to the exhaust bolt keeper it reads "060" or "090". The truck has under 13,000 miles on the odometer and came from a low use municipal setting. Any ideas? Attached Images __________________ 1966 GMC 1 Ton 305 V6 SM420 4 speed - retired Fire Dept Support Truck from Little Falls, NJ My GMC Photos

07-07-2015, 11:05 AM	#2
1963c-10 Registered User Join Date: Nov 2011 Location: fayetteville nc Posts: 10,338	Re: Help Identifying a tag I was thinking maybe engines been rebuilt and was bored .060 __________________ 1963 Short bed step side SBW 427 big block and borg warner T-16 HD 3 speed manual http://67-72chevytrucks.com/vboard/s...d.php?t=519869 1963 Short bed fleetside BBW 348 1st gen big block w/Powerglide http://67-72chevytrucks.com/vboard/s...d.php?t=619024 1964 Short bed trailer

07-07-2015, 09:23 PM	#3
TJ's Chevy Post Whore Join Date: Mar 2013 Location: Southern Oregon Posts: 10,384	Re: Help Identifying a tag No .060 over pistons available that I know of for a 305. __________________ 1966 Chevy C10 "Project Two Tone" http://67-72chevytrucks.com/vboard/s...d.php?t=596643 1964 GMC "Crustine" semi-build:http://67-72chevytrucks.com/vboard/s...d.php?t=665056 My youtube channel. Username "Military Chevy": https://www.youtube.com/channel/UC_h...fzpcUXyK_5-uiw

07-07-2015, 09:39 PM	#4
wcstory Registered User Join Date: Jun 2006 Location: Cape Cod, Ma. Posts: 236	Re: Help Identifying a tag I agree on doubting a rebuild. Everything I found from head gaskets to valves was stamped GMC. I was wondering about a special order tag. Being a fire support truck, it has double belt pulleys, dual batteries, etc. One thing is clear it was "build or unit 2591" there are grease pencil marks throughout the truck __________________ 1966 GMC 1 Ton 305 V6 SM420 4 speed - retired Fire Dept Support Truck from Little Falls, NJ My GMC Photos

07-08-2015, 01:40 PM	#6
wcstory Registered User Join Date: Jun 2006 Location: Cape Cod, Ma. Posts: 236	Re: Help Identifying a tag I had meant to mic the bore, but it slipped my mind. Heads are back on now. Posted via Mobile Device

07-08-2015, 01:54 PM	#7
1963c-10 Registered User Join Date: Nov 2011 Location: fayetteville nc Posts: 10,338	Re: Help Identifying a tag Did it look like an recent work had been done when you had the heads off? __________________ 1963 Short bed step side SBW 427 big block and borg warner T-16 HD 3 speed manual http://67-72chevytrucks.com/vboard/s...d.php?t=519869 1963 Short bed fleetside BBW 348 1st gen big block w/Powerglide http://67-72chevytrucks.com/vboard/s...d.php?t=619024 1964 Short bed trailer

07-08-2015, 02:03 PM	#8
wcstory Registered User Join Date: Jun 2006 Location: Cape Cod, Ma. Posts: 236	Re: Help Identifying a tag Everything I saw looked original. Head gaskets stamped "GMC", valves stamped "GMC", etc.... There was none of that damn silicone gasket material everyone loves. The head and deck surfaces had no swirl or scrape marks (till I started) Posted via Mobile Device



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