Author Topic: Top speeds!  (Read 20370 times)

Offline 1979C20

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Top speeds!
« on: January 16, 2011, 06:52:56 PM »
Last night on the way home from sycamore creek, I opened 'er up on the empty highway. I hit a top speed of 111mph on flat ground and maxed out my engine at 5050rpms. Kept her thetr for a good 3 miles or so. No issues. No oil pressure drop. Stayed at 200°f. What are your guys top speeda and max rpms at that speed? This is a 79 c20 woth a 350, qjet, headers, glasspacks dumped umder the cab with 4.11 gears and 265/75/16's.

EDIT: SM465 tranny, too.
« Last Edit: January 21, 2011, 06:34:48 PM by 1979C20 »
1979 SCLB C20 Q-jet 350 SM465 14b F.F. 4.10 G80
1989 GMC Suburban V2500 TBI350 TH400 4in lift 35's 14b SF

Offline Irish_Alley

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Re: Top speeds!
« Reply #1 on: January 16, 2011, 07:28:24 PM »
Lol 74 in my 79. But you have to use a GPS to get a good reading
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Offline screamin86

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Re: Top speeds!
« Reply #2 on: January 16, 2011, 07:47:42 PM »
ive had mine to 120 with the 31s gps checked was at about 4400 in 3rd/drive th350 trans 3.42 gears.
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Offline 4x4orbust

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Re: Top speeds!
« Reply #3 on: January 16, 2011, 08:08:48 PM »
had mine at 70 on the speedo once.  (33" tires, so really about 75 or so)  for about 20 seconds.  that was a white knuckle ride!!     tach'ed about 2500.  th350 with 3.08 gears  :(
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Offline Layne

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Re: Top speeds!
« Reply #4 on: January 16, 2011, 08:35:37 PM »
My buddy was driving my truckwhile I was following him, he had 115 with the 250, 3pd. Lol I think that's all it had too
77 c-10 - 77 400 86 700r4 "Emmy"
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88 sierra - reman 350 700r4 "Eleanor"
All normal practicality and rational money handling goes out of the window when it comes to my truck.

Offline beastie_3

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Re: Top speeds!
« Reply #5 on: January 16, 2011, 09:36:39 PM »
You let someone else drive 115 in your truck? Must be a good friend!

Offline Layne

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Re: Top speeds!
« Reply #6 on: January 16, 2011, 11:40:40 PM »
Let's just say I let him borrow it.... He got an earful. lol
77 c-10 - 77 400 86 700r4 "Emmy"
83 citation - 2.5L Four on the Floor!
88 sierra - reman 350 700r4 "Eleanor"
All normal practicality and rational money handling goes out of the window when it comes to my truck.

Offline 1979C20

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Re: Top speeds!
« Reply #7 on: January 17, 2011, 12:10:29 AM »
I used a gps speedo on my phone. I pushed my pedal as far it would and the rpms topped out at 5050 and couldnt go any faster sadly. Its 4spd manual.
1979 SCLB C20 Q-jet 350 SM465 14b F.F. 4.10 G80
1989 GMC Suburban V2500 TBI350 TH400 4in lift 35's 14b SF

Offline thirsty

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Re: Top speeds!
« Reply #8 on: January 17, 2011, 07:28:12 AM »
Back when my 86 was on the road 85mph with 33's and a manual tranny, That motor wouldn't turn much over 4k rpms.
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Offline ChYmAiL

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Re: Top speeds!
« Reply #9 on: January 17, 2011, 08:32:06 AM »
I have a 1980 250ci with a 1bbl holley carb... 3.08 final drive... 255-75-15 on the back, reached 81m/h. I still need 4 more to travel in time......

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Offline jackjeckel757

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Re: Top speeds!
« Reply #10 on: January 17, 2011, 09:12:38 AM »
I'm gonna have to get a gps to figure mine out, the speedo bounces too much and with smaller tires its not correct. It says I've been over 100 but I estimate it to be more like 85-90.

Offline 1979C20

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Re: Top speeds!
« Reply #11 on: January 17, 2011, 01:38:38 PM »
Do you have a cell phone? If so, how new is it? The new Android phones have all kinds of apps and I downloaded the free GPS Speeso app.
1979 SCLB C20 Q-jet 350 SM465 14b F.F. 4.10 G80
1989 GMC Suburban V2500 TBI350 TH400 4in lift 35's 14b SF

Offline Lt.Del

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Re: Top speeds!
« Reply #12 on: January 20, 2011, 09:30:11 PM »
<----- you see from my profile pic the fact that a '79 speedo is buried at 100mph.  I did that on I-95 coming from Washington D.C.  w/ the 383 and 3.08 rear on stock size tires.  I don't know how fast i got to, but I wasn't pushing it too much.  I still had more to go, but, I didn't want to lose my job AND I don't my tires to shred.  Most truck tires aren't exactly built for speed ratings-which scares me because my truck constantly wants to go fast on the interstate since it is a high gear rear and torquey engine.    I wish I had my gps on it. But then again, my gps sometimes reads I walk 268 mph (it's a hiking handheld gps that sometimes briefly loses signal)
« Last Edit: January 20, 2011, 09:34:38 PM by SgtDel »

Offline ChYmAiL

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Re: Top speeds!
« Reply #13 on: January 20, 2011, 09:58:45 PM »
my gps sometimes reads I walk 268 mph

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Offline 78 Chevyrado

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Re: Top speeds!
« Reply #14 on: January 21, 2011, 09:19:56 AM »
I got mine upto about 100mph when I first got it road worthy, and it still had some left, probably not too much though.  Since then It doesnt go over about 80mph.  It'll do it, but I won't.. ;)  I think when you hit 90+ the gas guage drops as fast as the odometer turns.
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