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#1 |
Registered User
Join Date: Feb 2009
Location: OKC OK
Posts: 489
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Highway Screamer!
I am 6 months into my build and finally cresting the hill on the downward slide, finally started some painting last night!
Its a 3/4t with a dana 60 reaend, and the saginaw 4spd top loader shes geared so low I just use 3rd and 4th, I can start out from stoplights in 3rd!Friends riding with me think its hilarous that I have a 2 speed (Low and high). So needless to say it screams at 65-70 mph 3200rpm, My question is should i get a new rearend or swap trannys or both, I dont really want an auto, I think a 5 speed would be cool, and I read a few of the S-10 tranny swap threads, but I just dont know if they will hold up. I eventually want to rebuild my stock 350 crate motor to 350-400 HP, any suggestions???
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"You can put lipstick on a pig, sure it's pretty pig, but it's still just a PIG... ![]() 71 ![]() |
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#2 |
Eat My Rust
Join Date: Jan 2007
Location: Cypress, Texas
Posts: 3,362
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Re: Highway Screamer!
What size tires? I moved up to a 31" x 10.5 truck tire and that helped out my highway cruising quite a bit. Other than that, with our D60s, it's the slow lane for us
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#3 |
Registered User
Join Date: Sep 2001
Location: Hacienda Heights, California USA
Posts: 474
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Re: Highway Screamer!
You might try getting a manual trans out of a newer full size GM truck. Or look into a V8 GM car with a stick shift, mainly the F bodies Camaros and Firebirds.
The S series truck's manual trans, might be a bit weak for a V8, especially if you plan on upgrading the stock 350. That's if you don't want to switch to an automatic trans. My 3/4 ton also screams at approx 70 mph. I say approx, cause the speedo bounces all over the place. That and with flowmaster 40 dumping just before the rear axle, all I hear is the exhaust. I am running Bridgestone Desert Dualers, 31" tall tires in an attempt to lower the rpms. The truck has a turbo 350 in it, at this time.
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'72 GMC custom camper 350/350 Last edited by spinning wheels; 04-05-2009 at 04:13 PM. |
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#4 |
its all about the +6 inches
Join Date: Jan 2001
Location: Hilliard Ohio
Posts: 2,693
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Re: Highway Screamer!
if you actually have a dana 60, then just get a gear swap in there.
If you have the eaton (much more common) then you are stuck with a tranny upgrade, or rear end swap Your cruise RPM makes me think you have a 4.10 gear... takin off in 3rd os a little rough on your clutch and the heat will damage your flywheel. |
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#5 |
Registered User
Join Date: Feb 2008
Location: Lake Stevens, WA
Posts: 623
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Re: Highway Screamer!
NV4500 and 3.73 rear. Nice combo
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#6 |
Special Order
![]() ![]() Join Date: Nov 2004
Location: Mt Airy, MD
Posts: 85,859
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Re: Highway Screamer!
What`s wrong with running 3,200rpm.That`s what we all did before o/d.I cruised my 4.10 equipped`71 Camper truck all over the country @ 70-80 mph.It seemed happy to me.Still have the original never rebuilt motor.Lower rpms is a good thing.But how much will it cost?You won`t hurt the truck running as it is.Most people are just used to o/d these days.
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"BUILDING A BETTER WAY TO SERVE THE USA"......67/72......"The New Breed" GMC '67 C1500 Wideside Super Custom SWB: 327/M22/3.42 posi.........."The '67" (project) GMC '72 K2500 Wideside Sierra Custom Camper: 350/TH350/4.10 Power-Lok..."The '72" (rolling) Tim "Don't call me a redneck. I'm a rough cut country gentleman" R.I.P. ~ East Side Low Life ~ El Jay ~ 72BLUZ ~ Fasteddie69 ~ Ron586 ~ 67ChevyRedneck ~ Grumpy Old Man ~ |
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#7 |
Registered User
Join Date: Apr 2007
Location: King City, Ontario, Canada
Posts: 974
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Re: Highway Screamer!
special K has a very good point.
by the time you have made the swap, how much money have you spent? how many years will it take to make that money back in gas SAVINGS? just think...3200 rpm...its right in its powerband ![]() ![]()
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- Jason If you can turn, Youre not going fast enough. Favorite caption: first car to 200 mph in the 1/4 mile, no parachute, drum brakes all the way around.. ..back when men were men. |
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#8 |
Eat My Rust
Join Date: Jan 2007
Location: Cypress, Texas
Posts: 3,362
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Re: Highway Screamer!
Fuel mileage is one issue.
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#9 |
Registered User
Join Date: Feb 2009
Location: OKC OK
Posts: 489
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Re: Highway Screamer!
You have a point Special-K, I have a 2002 Tahoe, and my wife drives a Hundai Sonota (yeah i know...) When you are used to these overdrives 3200-3500 at 65-7O Mph just seems like I'm running the heck out of the motor, turning lower rpms might gain me a few mpg's if I'm lucky, a gear set for my Dana 60 is under 200 and that might be what I'll try first, so a 3.73 would be the way to go then?
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"You can put lipstick on a pig, sure it's pretty pig, but it's still just a PIG... ![]() 71 ![]() |
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#10 |
Registered User
Join Date: Apr 2004
Location: Clanton, AL
Posts: 1,253
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Re: Highway Screamer!
Thats nothing! I have a '70 C-10 w/ 4.56 out back. I stepped up from 27" to 31" tires & it has helped a bit, but still way too low!
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85' CUCV M1009!!! The newest addition! 6.2diesel, Th400, NP208, & only 36k miles! 70' C-10 LWB Fleetside - Looking good these days! ![]() 05' Dodge Neon 88' Winner Escape Sport 1750 - 4.3v6 94' Seadoo SP 84' Honda TRX200, bare nekkid. Just a frame & tires. Always looking for another project or any good deal! ![]() |
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#11 |
Registered User
Join Date: Dec 2005
Location: louisville ky
Posts: 8
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Re: Highway Screamer!
My '71 C-20 is the same... eaton rear with the 4.11..... and its about to get swapped for a new frame with the leaf spring rear and a dana and 3.54 gears... i'm hoping to see a diffrence in cruise and still have enough bottom...
you should drive my 1930 AA ford.....the engine won't make it to 3000 rpm and its got a 6.60 rear axle ratio.... top speed 35 jeff
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71 camper special |
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#12 |
Special Order
![]() ![]() Join Date: Nov 2004
Location: Mt Airy, MD
Posts: 85,859
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Re: Highway Screamer!
I drove my CustomCamper/20 with 4.11s from Maryland to Taos,Durango,4 corners,North Rim,Sedona,and back and never gave it a though except when I was enjoying hearing that sweet pitch coming throgh the jalousy windows.
![]() These Dana60 trucks were available with 3.54s...better yet over 3.73s.My`72 has them and it runs great all around.It catches second with 12.50/33s and still rolls down the hiway nicely.
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"BUILDING A BETTER WAY TO SERVE THE USA"......67/72......"The New Breed" GMC '67 C1500 Wideside Super Custom SWB: 327/M22/3.42 posi.........."The '67" (project) GMC '72 K2500 Wideside Sierra Custom Camper: 350/TH350/4.10 Power-Lok..."The '72" (rolling) Tim "Don't call me a redneck. I'm a rough cut country gentleman" R.I.P. ~ East Side Low Life ~ El Jay ~ 72BLUZ ~ Fasteddie69 ~ Ron586 ~ 67ChevyRedneck ~ Grumpy Old Man ~ |
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#13 |
Registered User
Join Date: Jan 2006
Location: Seattle WA
Posts: 505
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Re: Highway Screamer!
I've got the Dana60 with 4.10s and have decided to keep it that way with my TH350. Some good points here - how many miles do you have to drive to get the cost back, etc.
I'm used to driving at a lower RPM so I thought I was killing it at 65, but I guess I'm not. ![]() One more thing - UltraBlue71 - M I Z....
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Curry in a Hurry: SB rebuild for my 71 C20 |
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#14 |
Registered User
Join Date: Feb 2009
Location: OKC OK
Posts: 489
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Re: Highway Screamer!
-ZOU...GO TIGERS! BIG 12 ROX!
I just want her to last another 38 years (or more) for me to enjoy with my kids and grandkids. Shes just gonna be garage furniture for the most part. The rudementary nature of the beast is part of the fun I suppose, low gears, 4spd, loud exhaust, windows down, vent windows swung open, floor vents open, me and my 3 boys ( all double buckled of course) headed out fishing or for an icecream cone. My old man loves these year trucks he always had one done or inwork when my brother and I went to visit him during summer break, back when we were little. Late (80's), I guess I really just want my kids to apperciate this old iron as much as I do, American craftsmanship, the last of the all steel Chevys!
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"You can put lipstick on a pig, sure it's pretty pig, but it's still just a PIG... ![]() 71 ![]() Last edited by UltraBlue71; 04-08-2009 at 12:45 AM. |
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#15 |
Registered User
Join Date: Jun 2005
Location: Midlothian, VA
Posts: 148
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Re: Highway Screamer!
This past weekend I installed a NP 833 into mine. I Love it, Why didn't GM sell more of these? I have a 2.7? rear and with the OD I'm turning about 1400 rpm at 65. Can't wait to run the first full tank to check the gas mileage, I've hit 18 highway before, is 20 possible in a flying brick?
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![]() 383 Stroker - Edlebrock Air Gap intake and 670 CFM Holley Street Avenger carb. Hooker Comp Headers w/ X-Pipe and 2.25 duals TKO-500 & 3.08:1 rear I Love HEMI's, they're soft & chewy! ![]() |
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#16 |
its all about the +6 inches
Join Date: Jan 2001
Location: Hilliard Ohio
Posts: 2,693
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Re: Highway Screamer!
at 1400 RPM, your MPG will probably drop.
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#17 |
Registered User
Join Date: Feb 2009
Location: OKC OK
Posts: 489
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Re: Highway Screamer!
LMN8ur what did that Np833 tranny come out of? Isnt that a 4 speed too? Are you running a gear vendors unit?
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"You can put lipstick on a pig, sure it's pretty pig, but it's still just a PIG... ![]() 71 ![]() |
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#18 |
Registered User
Join Date: Oct 2008
Location: great falls, mt
Posts: 82
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Re: Highway Screamer!
4.56's here from factory.... even with 33's it's ridiculous on the highway....
feel your pain... then again i am kinda hard on things, and if something breaks it gives me good reason to replace it with something.. "better" ![]() |
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