Highway Rpm Question !!! - The 1947 - Present Chevrolet & GMC Truck Message Board Network

MITCH1914 · 09-17-2002, 09:04 AM

i am planning on going to the river city auto fest in evansville in a couple of weeks. it is about a 140 mile ride from indy. here is my question: what is the maximum rpm that i can run for about 2 1/2 hours without hurting my engine.

i have a 373 posi and a 2200 stall. at 60 mph i'm at 3000 rpm. should i make this trip or should i trailer my truck to e-ville.

oh yeah my cooling system is pretty good it runs at 160 degrees on the highway.

what do yall think?

thanks

Woody · 09-17-2002, 09:08 AM

Mitch1914,

I have 3.73 gears in my 69 and run 275/50/15 tires. Not sure of the RPMs, but I run it down the interstate at 75-80mph all the time. Just keep an eye on your gauges (temp. ,oil pressure) and it should be fine.

MITCH1914 · 09-17-2002, 09:55 AM

what temp. does your truck run and what is the furthest you have driven your truck at that speed

thanks

HotRod929 · 09-17-2002, 10:48 AM

I drove my 1970 C/20 with Turbo 350 and 4.10 gears all the way accross the country doing like 70 - 75 mph all the way accross. He was fine the whole way accross.

HotRod

jmil1974 · 09-17-2002, 11:01 AM

I have Turbo 350, 3.08 gears, 275/60-15s and used to keep my freeway RPMs at a steady 3000+ all the time (gasp, was I speeding?!).

Like was already said, just watch the temp and oil gauge occasionally and you'll be dandy.

Woody · 09-17-2002, 12:48 PM

Mitch1914,

Well I must admitt it has been a while since I drove my truck. It has been in the basement getting a resto forthe last 1.5 yrs or so. It had a 350 but now has a '85 305 that has been in it for the last 5 or so years. 400t and 3.73 gears, with 275/50/15 tires. When I drive on the interstate I run 75-80. It has a 4 core rad. since it is an a/c truck. I use to drive it to Charlotte to the race in May every year loaded with an 8x12 foot wood platform, camping equipt, coolers, beer, beer, and more beer for the weekend in the infield. This year was the first 600 I've missed since 1983.

That is a 420 mile trip one way from Lexington KY. Over the mountions and all. Going up the big hills it would raise the temp by 20 or so degrees but was fine on the other side. It's hard to run slower because the rpm's would drop out of the power band. Keep it rolling around 75 and the hills didn't slow you down much. Below 70 and the hills would make you lose speed.

Good Luck and watch the gauges...

MITCH1914 · 09-17-2002, 12:58 PM

thanks for the feedback guys. i don't think i will have any problems taking the trip to e-ville from indy and back

mitch1914

THOR 50 · 09-17-2002, 07:13 PM

3.73 and stock size tire in my automatic truck 70MPH is 3800rpm

09-17-2002, 09:04 AM	#1
MITCH1914 Registered User Join Date: Mar 2001 Location: indianapolis,indiana,usa Posts: 506	Highway Rpm Question !!! i am planning on going to the river city auto fest in evansville in a couple of weeks. it is about a 140 mile ride from indy. here is my question: what is the maximum rpm that i can run for about 2 1/2 hours without hurting my engine. i have a 373 posi and a 2200 stall. at 60 mph i'm at 3000 rpm. should i make this trip or should i trailer my truck to e-ville. oh yeah my cooling system is pretty good it runs at 160 degrees on the highway. what do yall think? thanks

09-17-2002, 10:48 AM	#4
HotRod929 Registered User Join Date: Mar 2002 Location: Bondurant, IA but in Worcester, MA for school Posts: 767	I drove my 1970 C/20 with Turbo 350 and 4.10 gears all the way accross the country doing like 70 - 75 mph all the way accross. He was fine the whole way accross. HotRod __________________ 1970 Chevy C-20 350 V-8 Turbo 350 w/ shift kit Dana 60 w/ 4.10 gears AND Powr-Loc POSI New Additions: Summit Headers 135amp alternator Proform HEI Edelbrock 1406 600cfm carb Sunpro Tach Powr-Loc POSI Edelbrock Performer RPM Intake MSD 6A Ignition Box AIM: HotRod929 Visit My Site: http://1970chevy.netfirms.com/

09-17-2002, 11:01 AM	#5
jmil1974 Ain't we cute? Join Date: May 2002 Location: Friendswood, TX Posts: 700	I have Turbo 350, 3.08 gears, 275/60-15s and used to keep my freeway RPMs at a steady 3000+ all the time (gasp, was I speeding?!). Like was already said, just watch the temp and oil gauge occasionally and you'll be dandy. __________________ 69 C10 2WD LWB Fleet 350/350 power front disc conversion (6 lug disc kit from gmcpauls) and new engine, PS, A/C, fresh fluids, SHE DRIVES! FOR SALE $3900

09-17-2002, 07:13 PM	#8
THOR 50 Over worked under paid Join Date: May 2001 Location: Fort Myers, Florida Posts: 378	good luck 3.73 and stock size tire in my automatic truck 70MPH is 3800rpm __________________ Roger '69 C-10 with GMC front clip billet grill, 283CI, 400TH and 12bolt posiw/3.73 gears

09-17-2002, 09:08 AM	#2
Woody Registered User Join Date: Feb 2000 Location: Georgetown, KY, USA Posts: 631	Mitch1914, I have 3.73 gears in my 69 and run 275/50/15 tires. Not sure of the RPMs, but I run it down the interstate at 75-80mph all the time. Just keep an eye on your gauges (temp. ,oil pressure) and it should be fine.

09-17-2002, 09:55 AM	#3
MITCH1914 Registered User Join Date: Mar 2001 Location: indianapolis,indiana,usa Posts: 506	what temp. does your truck run and what is the furthest you have driven your truck at that speed thanks

09-17-2002, 12:48 PM	#6
Woody Registered User Join Date: Feb 2000 Location: Georgetown, KY, USA Posts: 631	Mitch1914, Well I must admitt it has been a while since I drove my truck. It has been in the basement getting a resto forthe last 1.5 yrs or so. It had a 350 but now has a '85 305 that has been in it for the last 5 or so years. 400t and 3.73 gears, with 275/50/15 tires. When I drive on the interstate I run 75-80. It has a 4 core rad. since it is an a/c truck. I use to drive it to Charlotte to the race in May every year loaded with an 8x12 foot wood platform, camping equipt, coolers, beer, beer, and more beer for the weekend in the infield. This year was the first 600 I've missed since 1983. That is a 420 mile trip one way from Lexington KY. Over the mountions and all. Going up the big hills it would raise the temp by 20 or so degrees but was fine on the other side. It's hard to run slower because the rpm's would drop out of the power band. Keep it rolling around 75 and the hills didn't slow you down much. Below 70 and the hills would make you lose speed. Good Luck and watch the gauges...

09-17-2002, 12:58 PM	#7
MITCH1914 Registered User Join Date: Mar 2001 Location: indianapolis,indiana,usa Posts: 506	thanks for the feedback guys. i don't think i will have any problems taking the trip to e-ville from indy and back mitch1914



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