How Fast Can A Squarebody Go?

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86suburbanNJ609

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I drive 75-80 mph on highway to and from work no problem 350/700/208 3:73 gears 33s. Tell you what at 75 and I gotta pass someone that thing downshifts and opens right up to 85 no problem gets a lil loose though just gotta go with ole betsy and she straightens right out.. Daily driver and getting 13mpg too cant believe it!!!
 

Rusty Nail

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Hay look!

It's that one guy. What's up dude?

My 88 tops out at 95 or so. No way in hell it'll do 100 as-is and it gots a chip! :banghead:
 

SquareRoot

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I daily drive my 79’ k30 crewcab dually. Has stock 350/sm465/205 with 4.10 and 235/85. Old dually will do every bit of 90mph at 4000rpm. Closer to 100mph on the down hills. Don’t think there’s any power after 4k rpm. Just keep my foot to the floor and the truck will run 80mph all day smooth n steady no problem. Only real downfall is the screaming exhaust and 5 mpg lol

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You got big balls to take your hand off the steering wheel at that speed just to take a pic. Lol
 

jake wells

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No way in hell i am driving that fast in square body i value my life to much and if you got in a head on collision kiss you lower body good bye when the engine comes through the firewall.
 

77 K20

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No way in hell i am driving that fast in square body i value my life to much and if you got in a head on collision kiss you lower body good bye when the engine comes through the firewall.

Depends on what you hit.

Could be a sweet jump!

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gotyourgoat

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I daily drive my 79’ k30 crewcab dually. Has stock 350/sm465/205 with 4.10 and 235/85. Old dually will do every bit of 90mph at 4000rpm. Closer to 100mph on the down hills. Don’t think there’s any power after 4k rpm. Just keep my foot to the floor and the truck will run 80mph all day smooth n steady no problem. Only real downfall is the screaming exhaust and 5 mpg lol

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And just how accurate are these gauges?

A dually pushing 95 and the gas gauge is pegged past full. I open the secondaries after leaving the gas station and I'm no longer reading at full or beyond.:33:
 

77 K20

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I had doubts on the accuracy of my speedometer but when I passed the wife in her Passat. She backed off at 100. I kept going. (backstory- quite often I would meet her for dinner in town and instead of driving home nicely following each other she takes off like a bat outta hell. Didn't feel like being left in the dust in my truck).

And it was amazing that my Softopper canvas safari top stayed on. I was quite amazed. The sides of it do get sucked in like one of those vacuum seal-a-meal bags.
 

Curt

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I don’t know how fast I was going,to be sure.The speedometer only went to 85,and given the amount it traveled past 85,I’d say 100-105.

Did it in a 1980 1/2 ton on one tons with 4.10 and 37” tires.Crate engine with fast burn heads and sm465.
 

Rusty Nail

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I don’t know how fast I was going,to be sure.The speedometer only went to 85,and given the amount it traveled past 85,I’d say 100-105.

Did it in a 1980 1/2 ton on one tons with 4.10 and 37” tires.Crate engine with fast burn heads and sm465.

Dude.
Download a GPS powered cell phone app. They have speedometer ones now.;)

I use cool niks

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Curt

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When I made my own land speed record,it was before civilian gps speed monitoring.

23-26 years old and didn’t know what I know now.Will I try it again,probably not.Don’t believe the top end on current 383 will appreciate those rpms.

However,I will say that 100 mph on 37s in that truck was smooth as silk.
 

Octane

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The way my k10 burns fuel I'm not sure that I can outrun the fuel gauge getting to 100 mph.I already have to shut the engine off just to fill it up at the pump.And those foreign gas station owners sure are friendly,when they see me coming they stand out at the curb smiling and waving me in.
 

ali_c20

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I went 110 one time on a straight stretch on the freeway with my k5 and it was really scary! 110 is guesstimated as my tach ends at 100...
I think it could go a little faster but I wasn't brave enough ever since to give it another shot.

th350/3.08 on 33" wheels.
 

Billy

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Let me begin with the obligatory disclaimer by saying that I'm not encouraging or suggesting that anybody go out and break any laws or try to set a record in one of these things.

But since it came up in another thread I thought it would be an interesting question. I was thinking that "In Theory" a factory truck would be hard pressed to make it to the triple digit mark. Given the relatively low horsepower of the engines of the era, and the stellar aerodynamics that has earned them their nickname, I'm going to guess that 100 MPH is out of reach. Or is it?

Anybody have one of those maximum speed calculators for gear ratios and tire diameter? Does anybody know the drag coefficient of one of our bricks?

What says the GMSB brain trust?

When i was a teenager (early 80's), my best friend had a 77 K5. We decided to see how fast it would go. On I-75, we hit 120 mph. We got off on the exit, turned back toward home, and did it again. It had a 4-speed, if that matters.
 

Doublenaughtspy

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I googled world's fastest square body and came up with this:

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They called it "Ms Misery" because it oiled down or crashed at EVERY track it went to. When that thing pulled up, everyone groaned because you were about to get a half hour or more to go get a sandwich while they clean its guts off the track.
 

Battlac40

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I used to drive a friend's minty 84 2wd Surbaban 350/400 factory setup through the mountains. Coming downhill I would crank it up to 90 before I felt that we would flip rounding the corners. It had some more pedal. :driver::headbang:
On the other hand my 81 350/350c/281 4wd gears out about 80 with 31's and 75 33's.:Stupid Me:
Old black 76 3/4 makes 70 feel good with a 350/400/205 setup but my front end, tires and shocks are absolute garbage!:boti:
 

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