Need help on gears for my 87 R10 and new 383 - Page 2 - The 1947 - Present Chevrolet & GMC Truck Message Board Network

UATahoe · 01-22-2013, 03:24 PM

Sounds good! If the deal checks out, i think i may go with that. The price is definitely right if everything is new.

MTCK · 01-22-2013, 04:33 PM

Make sure the spline count matches your current axles or it won't be quite as good a deal.
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UATahoe · 01-22-2013, 04:42 PM

Just checked actually. They are 28 spline so they see to be right for my 87
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UATahoe · 01-23-2013, 12:11 AM

Anybody have a recommendation for a good gear brand?
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MTCK · 01-23-2013, 01:52 AM

I think I have richmond gear in the front of my truck and and precision gear rear with G2 master install kits w/ timken bearings. No problems with any of it. As long as it sounds like you are thinking about gears, I'd get at least a 3.73 ratio, if not 3.90 with a limited slip so you can enjoy that 383...
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cory d · 01-23-2013, 02:24 AM

2.73's with overdrive? previous owner must have spent allot of time at the salt flats

UATahoe · 01-23-2013, 10:01 AM

I will say i am strictly going off of RPO codes. I havent opened up the diff to visually check. But given the way the truck moves on the road, 2.73's seem about right. LOL. A change is definitely needed

gchemist · 01-23-2013, 11:46 AM

Any tire bigger than 29" should run 3.73 gears with a 700R4. Even a stock engine. Stock engines like 1800-2200 RPM for cruising 70 MPH. LWB or lifted 4X4 don't benefit as much as a SWB or lowered truck. It's all about peak torque at cruise and aerodynamics of a "BRICK"!

UATahoe · 01-23-2013, 12:02 PM

Man, i appreciate the help and feedback guys. At first i was just focused on getting the new motor and getting it in and being done. LOL. I have since slowed down a little and have decided to do things right and that includes rebuilding the transmission while its out and addressing the old tired rear end. Its killing me to go slow but in the end it will be worth it i think.

I will definitely be going with 3.73 gears. Now i just have to find the best deal on a posi and 3.73's. I know it wont be cheap but hopefully there is a good deal out there somewhere.

Thanks again for all of the help!!

01-22-2013, 03:24 PM	#26
UATahoe Registered User Join Date: Mar 2012 Location: Huntsville, AL Posts: 1,000	Re: Need help on gears for my 87 R10 and new 383 Sounds good! If the deal checks out, i think i may go with that. The price is definitely right if everything is new.

01-22-2013, 04:33 PM	#27
MTCK Registered User Join Date: Dec 2009 Location: Fairbanks, AK Posts: 1,830	Re: Need help on gears for my 87 R10 and new 383 Make sure the spline count matches your current axles or it won't be quite as good a deal. Posted via Mobile Device __________________ -Marcus 1991 V3500 L29 454 4L80E NP205 D60/14 Bolt 4.56's 1984 K30 292 TH400 NP205 D60/14 Bolt 4.56's flat bed 7'6" Meyer Plow 2022 Silverado 3500 L8T Project Daily Driver Project Heavy Hauler Project Plow Truck

01-22-2013, 04:42 PM	#28
UATahoe Registered User Join Date: Mar 2012 Location: Huntsville, AL Posts: 1,000	Re: Need help on gears for my 87 R10 and new 383 Just checked actually. They are 28 spline so they see to be right for my 87 Posted via Mobile Device

01-23-2013, 12:11 AM	#29
UATahoe Registered User Join Date: Mar 2012 Location: Huntsville, AL Posts: 1,000	Re: Need help on gears for my 87 R10 and new 383 Anybody have a recommendation for a good gear brand? Posted via Mobile Device

01-23-2013, 01:52 AM	#30
MTCK Registered User Join Date: Dec 2009 Location: Fairbanks, AK Posts: 1,830	Re: Need help on gears for my 87 R10 and new 383 I think I have richmond gear in the front of my truck and and precision gear rear with G2 master install kits w/ timken bearings. No problems with any of it. As long as it sounds like you are thinking about gears, I'd get at least a 3.73 ratio, if not 3.90 with a limited slip so you can enjoy that 383... Posted via Mobile Device __________________ -Marcus 1991 V3500 L29 454 4L80E NP205 D60/14 Bolt 4.56's 1984 K30 292 TH400 NP205 D60/14 Bolt 4.56's flat bed 7'6" Meyer Plow 2022 Silverado 3500 L8T Project Daily Driver Project Heavy Hauler Project Plow Truck

01-23-2013, 02:24 AM	#31
cory d Registered User Join Date: Dec 2011 Location: Arlington WA Posts: 1,728	Re: Need help on gears for my 87 R10 and new 383 2.73's with overdrive? previous owner must have spent allot of time at the salt flats __________________ GMC C15 355 SM465 3.73 80 C10 cruiser build thread 79 short stepside crew cab. big and ugly. build thread

01-23-2013, 10:01 AM	#32
UATahoe Registered User Join Date: Mar 2012 Location: Huntsville, AL Posts: 1,000	Re: Need help on gears for my 87 R10 and new 383 I will say i am strictly going off of RPO codes. I havent opened up the diff to visually check. But given the way the truck moves on the road, 2.73's seem about right. LOL. A change is definitely needed

01-23-2013, 11:46 AM	#33
gchemist BAD BOW-Silverado XST Join Date: May 2000 Location: Senior Member from Austin, TX Posts: 6,431	Re: Need help on gears for my 87 R10 and new 383 Any tire bigger than 29" should run 3.73 gears with a 700R4. Even a stock engine. Stock engines like 1800-2200 RPM for cruising 70 MPH. LWB or lifted 4X4 don't benefit as much as a SWB or lowered truck. It's all about peak torque at cruise and aerodynamics of a "BRICK"! __________________ Gerardo a.k.a. Mad Chemist Silverado XST videos

01-23-2013, 12:02 PM	#34
UATahoe Registered User Join Date: Mar 2012 Location: Huntsville, AL Posts: 1,000	Re: Need help on gears for my 87 R10 and new 383 Man, i appreciate the help and feedback guys. At first i was just focused on getting the new motor and getting it in and being done. LOL. I have since slowed down a little and have decided to do things right and that includes rebuilding the transmission while its out and addressing the old tired rear end. Its killing me to go slow but in the end it will be worth it i think. I will definitely be going with 3.73 gears. Now i just have to find the best deal on a posi and 3.73's. I know it wont be cheap but hopefully there is a good deal out there somewhere. Thanks again for all of the help!!



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