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#1 |
Ebay Junky
Join Date: Oct 2003
Location: CO
Posts: 893
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Highway RPMs?
what do you think my rpms would be at 65mph?
turbo 400 trans with 3.08 rearend 28" tall tires also, whats a good rpm to be at at 65mph?
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1972 CHEVY C-10 SWB 2WD - Possible Typhoon 4.3 turbo drivetrain.. 1983 Chevy c10 swb 2wd - possible 350tbi supercharged... |
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#2 |
Cantankerous Geezer
Join Date: Aug 2002
Location: Bel Aire, KS
Posts: 6,264
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You should be around 2500 rpm, figuring some tire radius loss due to the vehicle weight. Driving rpm range for a sbc is 1800-2800 rpm.
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Fred There is no such thing as too much cam...just not enough engine. ![]() |
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#3 |
its all about the +6 inches
Join Date: Jan 2001
Location: Hilliard Ohio
Posts: 2,693
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Here you go..
3.07 gears 28 inch tall tires (275/60R15 on 9 1/2 inch wide rims) Th350 non lockup converter And one lead foot. |
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#4 |
Ebay Junky
Join Date: Oct 2003
Location: CO
Posts: 893
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i will be doing alot of highway driving with my truck, should i get rid of the turbo 400 and get a 700r4? if i could be at 2000 rpms or so, it would be easier on my motor and i would get better mpg, so maybe 700r4?
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1972 CHEVY C-10 SWB 2WD - Possible Typhoon 4.3 turbo drivetrain.. 1983 Chevy c10 swb 2wd - possible 350tbi supercharged... |
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#5 |
Registered User
Join Date: Nov 2004
Location: New Lenox,IL
Posts: 306
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Is that all that trucks got???? 90 MPH lead footed??.
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1985 Chevrolet C-30 454 1-TON Dooley 1969 CHEVROLET CST-10 PICK-UP Good memories 1999 Chevrolet Z71 Ext. cab 5.7L Good Memories With a quart of oil, and a gallon of gas, she won't let no other car pass!!!. ![]() ![]() |
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#6 |
Senior Member
![]() Join Date: Mar 2003
Location: Colfax-California
Posts: 8,550
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I doubt it he's only tach'n 3500, he is almost outta gas though
Last edited by kwmech; 02-06-2005 at 10:05 PM. |
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#7 |
Senior Member
![]() Join Date: Mar 2003
Location: Colfax-California
Posts: 8,550
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The 3.08s with a 700 will essentially make the rear axle a 2.21 final drive ratio.
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#8 |
Registered User
Join Date: Nov 2004
Location: New Lenox,IL
Posts: 306
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Hey longhorn man what type of engine and trans do you got in that thing??
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1985 Chevrolet C-30 454 1-TON Dooley 1969 CHEVROLET CST-10 PICK-UP Good memories 1999 Chevrolet Z71 Ext. cab 5.7L Good Memories With a quart of oil, and a gallon of gas, she won't let no other car pass!!!. ![]() ![]() |
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#9 |
its all about the +6 inches
Join Date: Jan 2001
Location: Hilliard Ohio
Posts: 2,693
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well, i think that truck is sittin engineless at themoment...(sold to chevye about the time you were joining the board with a knocking 305) but back then it had a 355 with mild porting on 2.02 882 heads, a *500 lift edelbrock cam* with rhodes lifters, flat top pistons, an edelbrock dual roller timing chain, performer RPM intake, and at that time, an Edelbrock 600 cfm carb.
*The guy i bought the engine off lost the cam card, and couldn't remember the specs, all he remembered was it was 500intake/501 exhaust...when i killed the engine I pulled it out and it did in fact have some HUGE lobes, but I couldn't verify anything.* The tranny was a stock Th350 with a 1900 RPM B&M converter. Not enough converter to let her idle in gear, but with the 3.07 gears, I couldn't put the converter that the cam needed, so i ended up popping it in neutral at every stop light...that gets old after 3 1/2 years. That thing wasn't all that great off the line...it had enough to make some smoke...but it really shined out on the open road. I had it wrapped to the M in MPH once, and still had RPMs to go, but I was on a 2 lane black top in texas (commonly refered to as a Farm to Market rd) which was way too narrow and hilly to be playing around like that on so i lifted. I took a pic of the speedo, but that was in the 35mm camera days, and the camera ended up doing a gravity check and the pic was ruined...along with 6 months worth of truck pics. That pic up there wasn't maxed out by far...I had to lift for the off ramp i was quickly headed to...that was here in Columbus a couple years ago. When i picked up the camera I was doin a hair over 100, but by the time I turned it on and it took the pic, I was already down to 92-ish. |
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#10 |
its all about the +6 inches
Join Date: Jan 2001
Location: Hilliard Ohio
Posts: 2,693
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BTW, back to the question at hand...smokin...honestly I never thought that 'normal' freeway driving was very bad at 2500 RPM. That was high enough to have some good power, yet low enough to get somewhat decent MPG...esp considering the engein that thing had in it. I got an average (both city/highway) of about 11 MPG, a best of 14 MPG (all freeway holding at 75 or so) and a low of 9 havin fun in town stop light to stop light.
It would take a whole lot of cruising to make the 700 pay it's self off, and it won't last nearly as long as a stock TH350 or TH400 would. (90% of the time this is correct, but there is that 10%...) There is the cool factor, and the minimal engine longevity factor...I say minimal becouse 2500 isn't all that hard on a motor. |
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#11 | |
Registered User
Join Date: Nov 2004
Location: "Under Montana skies."
Posts: 1,836
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Quote:
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'71 GMC K20 Suburban, '71 GMC K10 Suburban, '72 Chevy C10 CST Suburban, '72 Chevy K20 clunker pickup. |
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#12 |
its all about the +6 inches
Join Date: Jan 2001
Location: Hilliard Ohio
Posts: 2,693
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Yup...I know what you mean...my truck has 31 inch tall tires and 4.10's in the diff.
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#13 |
Senior Member
Join Date: Jan 2005
Location: Loveland Co.
Posts: 3,098
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3.08's with a 700R4 might be lugging it down a bit unless your really haulin'
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Chris 74 Custom Deluxe SWB 350/350/3.73’s 99 2wd Silverado RCSB 5.3/4L60/3.90’s http://www.classictrucks.com/feature...short_bed.html |
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#14 | |
Majician
Join Date: Nov 2004
Location: In the Middle
Posts: 329
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Quote:
http://www.tyres1.com/calculators.html Enter "1" for transfer case ratio if you have a 2wd. |
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#15 |
Registered User
Join Date: Feb 2004
Location: columbus,ohio
Posts: 201
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you should step up to big block gm land with a 273 and 472 cadillac to go too upper regions of freeway driving
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