Unknown engine year - The 1947 - Present Chevrolet & GMC Truck Message Board Network

fred_e81 · 04-10-2018, 10:37 PM

So I recently bought an 81 GMC Sierra. I was told that it had a later unknown year engine. The guy said it was a 350 but, I think it's a 305. Anyways, I want to purchase a new water pump for it and I'm lost as to what year I should purchase it for. It looks like an 89 style of engine. Any info would be greatly appreciated. Thank you in advance.

I'm lost in the sauce fellas, im coming from Air-cooled VWs to V8's. Seems the culture is the same though.

Bandit130 · 04-10-2018, 10:48 PM

I always remove old one and take with me to auto parts and get exact same one. That way there is no mistakes made. The best suggestion I can give.

69heavychevy · 04-10-2018, 11:02 PM

I have an older block, but I'm running the same serpentine belt set up you are. When I bought my water pump I just asked for one from a 93 Chevy C1500 with a 350.

GSP7 · 04-10-2018, 11:40 PM

I must live a sheltered life... Ive never seen a air filter, what ever it is, like that

fred_e81 · 04-10-2018, 11:43 PM

Gents thanks for the quick replies, you guys rock. I'll definitely take the old pump with me to compare and see to what engine it compares to. I'll keep the 93 engine in mind. As for the filter on the carb, it's actually a fogger for the propane system that's on the truck. I plan to remove it. I don't like the ugly tank that's in the back. Once again fellas thanks for the help!!

RWJJR · 04-11-2018, 06:41 AM

That engine will be stamped 5.7 or 5.0 on the back upper side of the block (well most Ive saw are anyway).

95 S_Trucker · 04-11-2018, 08:42 AM

It looks like a 88-90 with the stamped serpentine brackets. 91+ are cast aluminum.

**hatzie** · 04-11-2018, 11:22 AM

Evilbay the LP system.

83GMCK2500 · 04-11-2018, 12:04 PM

Quote:

Originally Posted by GSP7

I must live a sheltered life... Ive never seen a air filter, what ever it is, like that

LPG fuel kit, example: http://www.gotpropane.com/p565.html

**kwmech** · 04-11-2018, 03:17 PM

regardless of engine size you'll need a late model reverse rotation water pump, b'cuz of the serp belt

04-10-2018, 10:37 PM	#1
fred_e81 Registered User Join Date: Nov 2014 Location: El Paso, TX Posts: 78	Unknown engine year So I recently bought an 81 GMC Sierra. I was told that it had a later unknown year engine. The guy said it was a 350 but, I think it's a 305. Anyways, I want to purchase a new water pump for it and I'm lost as to what year I should purchase it for. It looks like an 89 style of engine. Any info would be greatly appreciated. Thank you in advance. I'm lost in the sauce fellas, im coming from Air-cooled VWs to V8's. Seems the culture is the same though. Attached Images

04-10-2018, 10:48 PM	#2
Bandit130 Registered User Join Date: Dec 2014 Location: Euless, Texas Posts: 510	Re: Unknown engine year I always remove old one and take with me to auto parts and get exact same one. That way there is no mistakes made. The best suggestion I can give. __________________ 1974 Cheyenne 10 LWB Stock 350 W/HEI /TH350/AC/4 BBL Quadrajet Mopar by Birth Chevy by Choice

04-10-2018, 11:02 PM	#3
69heavychevy Registered User Join Date: Jan 2007 Location: Garland,TX Posts: 431	Re: Unknown engine year I have an older block, but I'm running the same serpentine belt set up you are. When I bought my water pump I just asked for one from a 93 Chevy C1500 with a 350. __________________ 80 C10 SWB Step Side - 350 w/ vortec heads, TH350, 12-bolt 3.73

04-10-2018, 11:40 PM	#4
GSP7 Registered User Join Date: Sep 2012 Location: Idaho Posts: 623	Re: Unknown engine year I must live a sheltered life... Ive never seen a air filter, what ever it is, like that __________________ '81 K20 Silverado , '99 Dodge Cummins 4x4, '05 Dodge Cummins 4x4, Pinstriping-Lettering-Specialty Painting

04-10-2018, 11:43 PM	#5
fred_e81 Registered User Join Date: Nov 2014 Location: El Paso, TX Posts: 78	Re: Unknown engine year Gents thanks for the quick replies, you guys rock. I'll definitely take the old pump with me to compare and see to what engine it compares to. I'll keep the 93 engine in mind. As for the filter on the carb, it's actually a fogger for the propane system that's on the truck. I plan to remove it. I don't like the ugly tank that's in the back. Once again fellas thanks for the help!!

04-11-2018, 06:41 AM	#6
RWJJR Registered User Join Date: Feb 2005 Location: EAST TENNESSEE Posts: 233	Re: Unknown engine year That engine will be stamped 5.7 or 5.0 on the back upper side of the block (well most Ive saw are anyway). __________________ 1980 Silverado short bed 1993 GMC 1500 LS swap 2006 Lifted Z71 Crew Cab

04-11-2018, 08:42 AM	#7
95 S_Trucker Registered User Join Date: Oct 2009 Location: . Posts: 2,178	Re: Unknown engine year It looks like a 88-90 with the stamped serpentine brackets. 91+ are cast aluminum.

04-11-2018, 11:22 AM	#8
hatzie Moderator Join Date: Oct 2008 Location: Wentworth, NH Posts: 4,913	Re: Unknown engine year Evilbay the LP system. __________________ 1959 M35A2 LDT465-1D SOLD 1967 Dodge W200 B383, NP420/NP201 SOLD 1969 Dodge Polara 500 B383, A833 SOLD 1972 Ford F250 FE390, NP435/NP205 SOLD 1976 Chevy K20, 6.5L, NV4500/NP208 SOLD 1986 M1008 CUCV SOLD 2000 GMC C2500, TD6.5L, NV4500 2005 Chevy Silverado LS 2500HD 6.0L 4L80E/NP263 2009 Impala SS LS4 V8 RTFM... GM Parts Books, GM Schematics, GM service manuals, and GM training materials... 1973-1991 GM Light Truck Service, Unit/Overhaul, Wiring Manuals, Parts Books and Some 1968-1999 GM Service Training textbooks in PDF 1988-1998 GMT400 CK service manual project 1988-1993 GMT400 CK parts books. 1967-1972 GM Light, Medium, & Heavy Truck Service Manuals in PDF Please include at least the year and model in your threads. It'll be easier to answer your questions. And please let us know if and how your repairs were successful.

04-11-2018, 03:17 PM	#10
kwmech Senior Member Join Date: Mar 2003 Location: Colfax-California Posts: 8,389	Re: Unknown engine year regardless of engine size you'll need a late model reverse rotation water pump, b'cuz of the serp belt



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