C-20 highway rpm's

[Mmorgan32]

Originally Posted by sawyerrm

Read this old thread and thought I would check for my understanding. . .

Picking up a C20 next week in Fresno and driving back to Redwood City. Truck has 327, granny-4speed, p265/75 R16 and I assume the stock rear end 4.10?. The drive home is 180 miles of all interstate and flat except for the Altamont Pass (Rolling Stones / Hell's Angels ) which is 6-8% grade for three miles. From what I've read, I can stay to the right and if I stay up with traffic ~65 mph, I won't do any harm to the engine and just burn a lot a gas. Fill up every 100 miles and I should be good, right?

After getting home, I can tweak the drive train to get it suited for a daily drive commute truck.

I make that drive all the time going from Fresno to half moon bay. I take 99 to 152 over Pacheco pass down to 101, 85, then 280. My truck is a 70 c20 35/350. I do have a crate engine with a cam in it and I drive about 70 and it's right at 3k rpms and it drives great now when I hit 75-80 it gets up to 34-35k and I get a little nervous but it still does it fine with no problems and my truck is not restored but I do check all my fluids often just to be sure. I love the way my c20 drives I've had a c10 and when it comes to just driving I think the 20 is way more comfortable and you don't have to worry about the ass end whipping out then you hammer down on the gas

[Sicklajoie]

Originally Posted by Mmorgan32

when I hit 75-80 it gets up to 34-35k and I get a little nervous but it still does it fine with no problems

Wow, that's some SERIOUS gear!!!

[conoco]

I know this is an old thread but I have a 1972 gmc k2500 with the eating. And 4.10. I also have a 4inch lift and 35s

40-50 I am around 2000-2500 rpms.

55-65 I am at 3000-3400 rpms. This is my daily driver and my fishing truck in the summer. I go 65-70 all day long for long stretches often and have no problems. I do have a 383 stroker with 10 grand on it also so I am sure that helps. When I had bo lift and stock tires it would scream around 3700-4000 rpms. It was a bit much but still drove fine if you worw ear plugs lol

[tdangle]

Before I swapped in an overdrive auto trans, I was running around 3000 at 60 MPH 4.10 gears with TH350 and 265/75R16 tires. Now right at 2000.

[conoco]

Originally Posted by tdangle

Before I swapped in an overdrive auto trans, I was running around 3000 at 60 MPH 4.10 gears with TH350 and 265/75R16 tires. Now right at 2000.

I am looking to order the gear vendors of unit for my th350. I should be ready to order hy summer. That will be the best upgrade I could make to my truck and cant wait.

[Andy4639]

When we bought the 64 SS Impala I told my dad I wanted a over drive to replace the 2 speed power glide. He asked why and I said to help it on driving it on long trips. He replied we drove these cars and trucks at 70 MPH back in the 60's with no problems. Gas mileage wasn't a concern like now. Gas prices where below a dollar. The car/truck didn't care it was built to drive them, short distances are long didn't matter.
The 64 still has the power glide and it runs fine.