3/4 ton gearing question - The 1947 - Present Chevrolet & GMC Truck Message Board Network

mikep · 11-13-2002, 01:03 AM

Been thinking about switching to an overdrive tranny but cant justify spending $1500-$2000 on an NV2500 . It'd take years to make up the gas cost savings and automatics just plain suck so that route isn't an option.

What I'm thinking about now is going to a higher gear ratio and replacing the close ratio 4 speed I have with a standard granny gear type. That way I'd keep the low first gear but I could have decent mileage in 4th. Ive got 3.54 gears in the Dana 60. Problem is I dont think Danas came with anything higher than 3.31's or so and I'd like to keep the 8 lug rear end. Another problem is that I have coil springs so I am limited to 67-72 rear ends unless I feel like changing around a later corporate 14 bolt. Did Eatons come with higher gears such as 3.07 . Maybe I could find someone who'd trade a posi 3.54 dana for a 3.07 geared posi eaton if they exist. Maybe I'm screwed and am just too picky.

crazy longhorn · 11-13-2002, 01:19 AM

It sounds to me that you have a pretty good combo. a close ratio 4spd & 3.54 gears......what the tire height....about 30"? rpms on the road should be decent. as perf oriented, that truck 4spd has too wide spacing between the gears to be fun . I run 4.10 gears on a 28" tire.......that sb revs a little on the hyway!

mikep · 11-13-2002, 01:25 AM

Its a good running combo but the mileage will be a killer when I have to start commuting over 100 miles a day next year so I'm trying to come up with alternatives. I'm REALLY not into automatics and those overdrive 5 and 6 speed manual trannies are out of my price range.

I was able to bust the tires loose at 70 miles an hour today. Try that with an automatic!

crazy longhorn · 11-13-2002, 02:02 AM

Yea the old longhorn will bust em loose going into pass gear, then bust em loose shifting back up.......not as much fun as a stick to drive tho! I have been lookin at 5 & 6 speeds also, & come to the same conclusion.....that OD stick trans would take a loooong time to pay for itself! that tremmec TKO looks like a nice box, but runs right at $2000. Im runnin a hydro, so add a lakewood with blocksaver,billet wheel& perf clutch, & the price goes out of site real quick.....

cableguy0 · 11-13-2002, 02:03 AM

well for traveling that far i'd honestly buy a little beater car that gets 40mpg. if u want gas mileage u got the wrong vechile and btw i can break the tires loose at 70 mph goin straight with an auto chirps 3rd at around 100 also

bigjimzlll · 11-13-2002, 02:16 AM

hmmmm...at 70 im at 5500 in 2nd gear..I will get a little sideways going into 3rd though...I did a burn out for my boss the other day...I guess the road didnt have to good of traction...I went through 1st 2nd and 3rd..when it grabbed in third..it down shifted and started all over again..lol..it was great..must be 200yards of my expensive rubber in front of my job

Brad · 11-13-2002, 06:18 AM

Can I have dibs on that close ratio 4 speed if you get rid of it?

mikep · 11-13-2002, 07:59 AM

I'd probably keep the tranny for a future project. Not that many around. I do know where another close ratio M 28 New Process 435 tranny just like mine is in a junkyard though if anyone is interested. Its just like driving a car. You can use all 4 gears.

Mike C · 11-13-2002, 08:22 AM

3.54 is the lowest numeric gear available in the Dana while 3.90 are the lowest gear for the Eaton. Buy another car. It is cheaper than NV4500 conversion and will save wear and tear on your truck. It will save you money as well because you will never get better than 17 mpg or so in the truck, but a $1500 VW Golf will get 30+ on the road, paying for itself in 24 months or so with that commute! You may not have considered that, but there are quite a few interesting econo-boxes out there.

11-13-2002, 01:03 AM	#1
mikep Used to have a truck Join Date: May 2002 Location: port orchard WA Posts: 1,552	3/4 ton gearing question Been thinking about switching to an overdrive tranny but cant justify spending $1500-$2000 on an NV2500 . It'd take years to make up the gas cost savings and automatics just plain suck so that route isn't an option. What I'm thinking about now is going to a higher gear ratio and replacing the close ratio 4 speed I have with a standard granny gear type. That way I'd keep the low first gear but I could have decent mileage in 4th. Ive got 3.54 gears in the Dana 60. Problem is I dont think Danas came with anything higher than 3.31's or so and I'd like to keep the 8 lug rear end. Another problem is that I have coil springs so I am limited to 67-72 rear ends unless I feel like changing around a later corporate 14 bolt. Did Eatons come with higher gears such as 3.07 . Maybe I could find someone who'd trade a posi 3.54 dana for a 3.07 geared posi eaton if they exist. Maybe I'm screwed and am just too picky. __________________ No truck :-(

11-13-2002, 01:19 AM	#2
crazy longhorn Fabricate till you "puke" Join Date: Jun 2002 Location: Ill Posts: 9,402	It sounds to me that you have a pretty good combo. a close ratio 4spd & 3.54 gears......what the tire height....about 30"? rpms on the road should be decent. as perf oriented, that truck 4spd has too wide spacing between the gears to be fun . I run 4.10 gears on a 28" tire.......that sb revs a little on the hyway! __________________ 69 longhorn,4" chop,3/5 drop, 1/2 ton suspension/disc brakes,1 1/2" body drop,steel tilt clip, 5.3/Edelbrock rpm intake/600 carb, Hooker streetrod shorties,2 1/2" exhaust/ H pipe/50's Flows , 6 spd Richmond trans,12 bolt/ 3.40 gears....

11-13-2002, 01:25 AM	#3
mikep Used to have a truck Join Date: May 2002 Location: port orchard WA Posts: 1,552	Its a good running combo but the mileage will be a killer when I have to start commuting over 100 miles a day next year so I'm trying to come up with alternatives. I'm REALLY not into automatics and those overdrive 5 and 6 speed manual trannies are out of my price range. I was able to bust the tires loose at 70 miles an hour today. Try that with an automatic! __________________ No truck :-(

11-13-2002, 02:02 AM	#4
crazy longhorn Fabricate till you "puke" Join Date: Jun 2002 Location: Ill Posts: 9,402	Yea the old longhorn will bust em loose going into pass gear, then bust em loose shifting back up.......not as much fun as a stick to drive tho! I have been lookin at 5 & 6 speeds also, & come to the same conclusion.....that OD stick trans would take a loooong time to pay for itself! that tremmec TKO looks like a nice box, but runs right at $2000. Im runnin a hydro, so add a lakewood with blocksaver,billet wheel& perf clutch, & the price goes out of site real quick..... __________________ 69 longhorn,4" chop,3/5 drop, 1/2 ton suspension/disc brakes,1 1/2" body drop,steel tilt clip, 5.3/Edelbrock rpm intake/600 carb, Hooker streetrod shorties,2 1/2" exhaust/ H pipe/50's Flows , 6 spd Richmond trans,12 bolt/ 3.40 gears....

11-13-2002, 02:03 AM	#5
cableguy0 Senior Member Join Date: Apr 2000 Location: Delta,Pa Posts: 14,948	well for traveling that far i'd honestly buy a little beater car that gets 40mpg. if u want gas mileage u got the wrong vechile and btw i can break the tires loose at 70 mph goin straight with an auto chirps 3rd at around 100 also __________________ Owner of North Point Car Care in Dundalk Md. We specialize in custom exhaust on both modern and classic vehicles. We are a full service auto shop from classics to modern vehicles. Feel free to contact me with questions. I will give a 10% discount to any board member. Last edited by cableguy0; 11-13-2002 at 02:19 AM.

11-13-2002, 02:16 AM	#6
bigjimzlll Senior Member Join Date: Dec 2001 Location: Redding,CA...USA Posts: 4,736	hmmmm...at 70 im at 5500 in 2nd gear..I will get a little sideways going into 3rd though...I did a burn out for my boss the other day...I guess the road didnt have to good of traction...I went through 1st 2nd and 3rd..when it grabbed in third..it down shifted and started all over again..lol..it was great..must be 200yards of my expensive rubber in front of my job __________________ It's called "drag racing" if they called it "tic..tic..WHAM!..BANG! F*&K!!!", they'd have to keep the magazines under the counter with the other men's publications click the clicky to join the site.... http://67-72chevytrucks.com/vboard/payments.php 67 lwb..first hotrod in 25 years..540 best ET is 9.45 @ 141.44 Anderson,CA

11-13-2002, 06:18 AM	#7
Brad Out of the carpool lane. Join Date: Jan 2000 Location: Clark Co, WA Posts: 5,672	Can I have dibs on that close ratio 4 speed if you get rid of it? __________________ 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...

11-13-2002, 07:59 AM	#8
mikep Used to have a truck Join Date: May 2002 Location: port orchard WA Posts: 1,552	I'd probably keep the tranny for a future project. Not that many around. I do know where another close ratio M 28 New Process 435 tranny just like mine is in a junkyard though if anyone is interested. Its just like driving a car. You can use all 4 gears. __________________ No truck :-(

11-13-2002, 08:22 AM	#9
Mike C Registered User Join Date: Dec 1999 Location: Austin, TX, USA Posts: 7,728	3.54 is the lowest numeric gear available in the Dana while 3.90 are the lowest gear for the Eaton. Buy another car. It is cheaper than NV4500 conversion and will save wear and tear on your truck. It will save you money as well because you will never get better than 17 mpg or so in the truck, but a $1500 VW Golf will get 30+ on the road, paying for itself in 24 months or so with that commute! You may not have considered that, but there are quite a few interesting econo-boxes out there. __________________ 44 Willys MB 52 M38A1 64 Corvette Coupe 68 Camaro 'vert LT1 & TH700 69 Z/28 355 12.6's @110 69 Chevy Short Step 4 1/2"/7" drop 72 Jimmy 4WD 4spd 4" & 35's 02 GMC 2500HD 4x4 Duramax



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