rearend ratio on Astro van - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Brad · 01-09-2003, 09:30 PM

Would anyone happen to know what rearend ratio an Astro van came with?

71k5 · 01-09-2003, 09:39 PM

What year? If it's 90 or newer, you can call your GM parts guy and give him the last 8 digits of your VIN, or the VIN of the vehicle that "donated" the rear end and he/she can give you the ratio.

ChevLoRay · 01-09-2003, 09:53 PM

I special-ordered one in '88, 8-passenger seating. Stock rear end was a 3.42, but I added positraction to the specs. I believe they also had a 3.23 (but not positive). There may have been a shorter ratio option, too. I am not sure, but I think a 3.73 was also available.

Longhorn Man · 01-10-2003, 01:46 AM

try poping the cover off and counting the teeth. I'll bet the oil is original anyways.

Bilgewiper · 01-10-2003, 09:41 AM

I bought a new GMC Safari in '93 and it had a optional 3.73 posi with the trailer tow option.......so I know that ratio was avalible

JJR · 01-10-2003, 10:10 AM

I picked 1989 and found the following ratios: 2.73 (GU2), 3.08(GU4), 3.23(GU5), 3.42(GU6), 3.73(GT4) and 4.10(GT5). A good site for this kind of info is the junkyard search engine www.car-parts.com You can input the year and model of the vehicle in question and search for a rear axle assembly and it will come back with the available ratios so you can match what you have.

Longhorn Man · 01-10-2003, 12:08 PM

JJR...sweet link, thanks.

Brad · 01-10-2003, 03:40 PM

Wow! Thanks guys. I can't take the cover off, because it doesn't belong to me. I'll get the code and figure it out that way.

Basically, I'm just trying to get a feel for how a 700r4 would feel in my truck. The Astro van is about the same weight as our trucks and the 4.3 is similar to my I6. Again, just trying to get a rough idea of acceleration, response, driveability, etc..

imaindianoutlaw · 01-10-2003, 04:49 PM

mine was a 3.73 and that thing ripped! rear was starting to go though!

01-09-2003, 09:30 PM	#1
Brad Out of the carpool lane. Join Date: Jan 2000 Location: Clark Co, WA Posts: 5,673	rearend ratio on Astro van Would anyone happen to know what rearend ratio an Astro van came with? __________________ 1968 C-10 SWB, 5.7 Vortec/700R4/3.73 posi, Torch Red 1968 Camaro, 250/Powerglide, all original (No, I'm not gonna drop a 350 in it!...Jeez!) 2000 Honda VFR in the faster yellow! 2008 Husqvarna TE-610 1967 C-10 SWB 'Six Appeal'-Gone but not forgotten...

01-09-2003, 09:53 PM	#3
ChevLoRay Old Skool Club Join Date: Jun 2001 Location: Benton, AR "The Heart of Arkansas" Posts: 10,880	I special-ordered one in '88, 8-passenger seating. Stock rear end was a 3.42, but I added positraction to the specs. I believe they also had a 3.23 (but not positive). There may have been a shorter ratio option, too. I am not sure, but I think a 3.73 was also available. __________________ Member Nr. 2770 '96 GMC Sportside; 4.3/SLT - Daily driven....constantly needs washed. '69 C-10 SWB; 350/TH400 - in limbo The older I get, the better I was.

01-10-2003, 09:41 AM	#5
Bilgewiper Registered User Join Date: Dec 2002 Location: Citrus Heights Ca. Posts: 186	I bought a new GMC Safari in '93 and it had a optional 3.73 posi with the trailer tow option.......so I know that ratio was avalible __________________ Ethan '71 C-10 LWB Cheyenne 85K miles. "Time spent Boating is NOT deducted from ones lifespan".

01-10-2003, 10:10 AM	#6
JJR Registered User Join Date: Apr 2000 Location: Leesburg, GA Posts: 746	I picked 1989 and found the following ratios: 2.73 (GU2), 3.08(GU4), 3.23(GU5), 3.42(GU6), 3.73(GT4) and 4.10(GT5). A good site for this kind of info is the junkyard search engine www.car-parts.com You can input the year and model of the vehicle in question and search for a rear axle assembly and it will come back with the available ratios so you can match what you have. __________________ FOUNDING MEMBER OF THE DRUM BRAKE CLUB Second Owner 70 C-10 Second Owner 93 GMC C1500 Third Owner 99 C2500 Crew Cab Short Bed

01-10-2003, 03:40 PM	#8
Brad Out of the carpool lane. Join Date: Jan 2000 Location: Clark Co, WA Posts: 5,673	Wow! Thanks guys. I can't take the cover off, because it doesn't belong to me. I'll get the code and figure it out that way. Basically, I'm just trying to get a feel for how a 700r4 would feel in my truck. The Astro van is about the same weight as our trucks and the 4.3 is similar to my I6. Again, just trying to get a rough idea of acceleration, response, driveability, etc.. __________________ 1968 C-10 SWB, 5.7 Vortec/700R4/3.73 posi, Torch Red 1968 Camaro, 250/Powerglide, all original (No, I'm not gonna drop a 350 in it!...Jeez!) 2000 Honda VFR in the faster yellow! 2008 Husqvarna TE-610 1967 C-10 SWB 'Six Appeal'-Gone but not forgotten...

01-09-2003, 09:39 PM	#2
71k5 Registered User Join Date: Feb 2002 Location: Manchester, PA Posts: 138	What year? If it's 90 or newer, you can call your GM parts guy and give him the last 8 digits of your VIN, or the VIN of the vehicle that "donated" the rear end and he/she can give you the ratio.

01-10-2003, 01:46 AM	#4
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	try poping the cover off and counting the teeth. I'll bet the oil is original anyways.

01-10-2003, 12:08 PM	#7
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	JJR...sweet link, thanks.

01-10-2003, 04:49 PM	#9
imaindianoutlaw GMC SHORT FLEET F/S Join Date: Jun 2000 Location: SOUTH WILLIAMSPORT PENNSYLVANNIA Posts: 2,117	mine was a 3.73 and that thing ripped! rear was starting to go though! __________________ CHARLES WADE HEIN HVACR FOREMAN. LEWISBURG U.S.P.



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