How fast will these things go, anyway?

[Oberon67]

The subject line says it. What's the fastest you've gone in a square body, either in acceleration or top speed?
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[flashed]

Mine is a 74 short step with 3 on the tree and a 250 /6 cylinder so not very fast .

[Oberon67]

Originally Posted by flashed

Mine is a 74 short step with 3 on the tree and a 250 /6 cylinder so not very fast .

I have the same drivetrain in an '81 long bed. A grocery-getter for sure, but I think I could bury the 85mph speedometer if I wanted to.

I haven't tried it. The reward doesn't seem worth the risk to me.
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[TwoFiftyShifter]

100 in my 87 V20. 4 speed 350. It wouldnt pull anymore after that;

[KQQL IT]

1/4 mile

[Oberon67]

Originally Posted by KQQL IT

1/4 mile

Wow... Not too shabby!
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[chrismoore701]

I had my speedo pointed straight down. Put two quarts of oil back in after that run

[Malo83]

Originally Posted by Oberon67

Wow... Not too shabby!
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That's nothing, I can do that coming down the grapevine from LA to Bakersfield

[KQQL IT]

Originally Posted by Malo83

That's nothing, I can do that coming down the grapevine from LA to Bakersfield

Malo83 I have that double hump transmission crossmember, free to a good home.

[Malo83]

Originally Posted by KQQL IT

Malo83 I have that double hump transmission crossmember, free to a good home.

PM sent.

[esbstuff]

Originally Posted by Oberon67

The subject line says it. What's the fastest you've gone in a square body, either in acceleration or top speed?
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1990 or so... 78 k10, 350, 4-speed, 205, 3.07's. I had the speedo pointed straight down and bouncing one night. 3 wide on a 2 lane interstate with a couple buddies. I think the story was the last one at the party had to buy beer... I didn't have to buy! Too afraid I would go splat now.

[Jake Wade]

Originally Posted by KQQL IT

1/4 mile

That's impressive for a Small block truck if NA

[KQQL IT]

Originally Posted by Jake Wade

That's impressive for a Small block truck if NA

Yeah, for now.
Just rebuilt it with better rods and opened up ring gaps.
Try a hundred shot out of the hole is the plan.

[D13]

1982 250 3ott 3.43 geared 3/4 ton, 80 is absolute limit.
1987 6.2 diesel 7004 3.08 geared 1/2 ton, fastest is 75, truck felt rock solid, issue was the noises under the hood.
I would suspect with a reasonable motor and OD trans with good gears that 120 would easily be possible. I read somewhere (Jim Feuling in CC in the 90's maybe?)that if the tailgate is open over 120 or so the vacuum bubble will close it - so I sure wouldn't want to try higher speed corners without some rear down force.

[phillip123hastings]

So not really fast whatsoever.

[KQQL IT]

Originally Posted by phillip123hastings

So not really fast whatsoever.

3.08's @ 5500 with a 27" tire was way way faster that they should ever go on a S rated tire.
Thought the driveshaft was coming thru the floor when I lifted off the gas.

[Matt Man]

I had mine at about 90mph to test out driveshaft vibration when I had it rebuilt and shortened. Felt stable, but the wind noise was awful. I tried to push it farther as well but wouldn't go any faster. Oh well its a 81 4x4 pickup, not meant for speed haha.

[foamypirate]

Calculator says I should have been doing about 112 based on RPM (about 4200) in my 305/TH350/3.08/29" tire 84' LWB, but I have no idea how much converter slip was going on. Pedal was on the floor for several miles (sick baby in a truck with no AC in 97* temps, was trying to get home to get her cooled down ASAP). Wide open toll road, thankfully. Realistically, probably closer to 95mph based on how quickly I was passing people.

In my 88' R20 crewcab, max I've been is 90mph, testing acceleration with the LQ9/4L80E/4.10 combo. Speed limiter is 98mph, and the driveshaft is only good until roughly 115mph anway. I feel no need to take this one any faster than 90mph.

[Oberon67]

Originally Posted by Matt Man

I had mine at about 90mph to test out driveshaft vibration when I had it rebuilt and shortened. Felt stable, but the wind noise was awful. I tried to push it farther as well but wouldn't go any faster. Oh well its a 81 4x4 pickup, not meant for speed haha.

I'm thinking someone... Not me, someone who can build... should put together a square-body for Bonneville.

The World's Fastest Squarebody.
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[mongocanfly]

There's already a square body salt truck...210mph.http://67-72chevytrucks.com/vboard/s...d.php?t=473510

[mikentosh]

LS motors and lowered trucks are a wonderful thing...I took Cannonball C10 down to LA a few weekends ago and got into a fast moving crowd of Friday evening traffic. It was more than happy to cruise at triple digit speeds on and off for a couple of hours. In fact 6th gear is only useful above highway speed as its doing 2000 rpm at 80mph. I'm attributing the stability to lack of airflow under the truck and wide track; the front air dam sits only a couple of inches off the pavement.

Downside to this is that vertical windshield collects a lot of bugs at speed haha

Got a nice photo of it just off the 5 in Coalinga too

[Oberon67]

Originally Posted by mongocanfly

There's already a square body salt truck...210mph.http://67-72chevytrucks.com/vboard/s...d.php?t=473510

Interesting... But I bet someone here could beat it.
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[Alex V.]

Fastest I've had my '85 C3500 (454/TH400, 4.10's) is 85, but it wasn't done yet. 90 wouldn't be too hard, and I think it'd break 100 but everything under there is spinning so fast at that speed I'd rather preserve the truck than take the chance.

[mongocanfly]

My 81 c30 with 6.0, nv4500 and 4.10s will hit a 100 before you know it..when they had it on the dyno they had it showing 140..

[Big Port Jimmy 6]

Funny, Ive been thinking of taking my CCSB to the ECTA in Wilmington for the first race next year. It should be a C/PP or C/MP. No real shot at the record as C/PP is a 163 and change. Maybe run up in B? 5.3/4l60e 3.42 gears 29 inch tall tire 3500 through the traps is 130ish but that would be a real maybe. 115-120 is more realistic. Just got to run the numbers and buy some stuff.