Daily a 71-72 k10/20

[72 k15]

Anyone out here daily a 71-72 k10/20 I will occasionally drive on the interstate about 300 mile round trip, speed limit is 75mph so I’m assuming I’ll need overdrive. How’s reliability with a stock truck? How is starting in the winter? It gets to be pretty cold up here -20 isn’t uncommon.

[71K1500]

My son uses his daily year round. Its a 70 GMC 4x4. Motor is a 5.7 with tbi from a late 80s truck with 700R4 trans. No problems but he does plug it in during cold spells.
I had a 72 4x4 when he was little that I used all year. It was original with a quadra jet carb.
As long as maintanance is kept up I dont see a reason to not use them.

Jeff

[72 k15]

Originally Posted by 71K1500

My son uses his daily year round. Its a 70 GMC 4x4. Motor is a 5.7 with tbi from a late 80s truck with 700R4 trans. No problems but he does plug it in during cold spells.
I had a 72 4x4 when he was little that I used all year. It was original with a quadra jet carb.
As long as maintanance is kept up I dont see a reason to not use them.

Jeff

The 3 main things im worried about would be reliability, cold starting, highway driving. I dont think im to worried about the cold now or highway as I would drop a overdrive unit in.

[truckster]

I daily drive my 72 Blazer. It starts every time and gets me wherever I'm going.

As far as overdrive, what engine/transmission/rear end/tire size are you running?

[titan1587]

There’s a thread about 2 posts away with exact same question

[72 k15]

Originally Posted by truckster

I daily drive my 72 Blazer. It starts every time and gets me wherever I'm going.

As far as overdrive, what engine/transmission/rear end/tire size are you running?

Well, im trying to figure out if I would need one and im thinking I will, speed limit is 75 and traffic goes 80. Im basically debating selling my 02 2500HD and buying a 71-71 4wd for a daily and trying to see if it is feasible for what I do. I really only would need to drive highway 1 time a year for hunting 120 miles away.

[truckster]

I have a 350/350 with 3.73 gears and 33" tires. It runs fine at 80.

[72 k15]

Originally Posted by truckster

I have a 350/350 with 3.73 gears and 33" tires. It runs fine at 80.

At 3000 RPM? can’t imagine that’s decent for the motor or gas milage.

[jocko]

Originally Posted by 72 k15

At 3000 RPM? can’t imagine that’s decent for the motor or gas milage.

Yes that combo is a hair over 3000 RPM at 80. The tires help, stock-ish 30" tires would be closer to 3300 rpm.

3000 on the highway wasn't that uncommon back in the land before overdrives - but now that we're used to cruising at 2100 RPM, 3000 feels like it's screamin. Doesn't really hurt the engine, per se, but it does affect fuel economy of course.

[gmc684x4]

-50 my truck in the back yard was the only truck in the yard to start
68 gmc 4x4 350 4x4 .
Good cold crank battery good tune up good antifreeze I always mix 60 40 synthetic oil good to go

[72 k15]

Originally Posted by jocko

Yes that combo is a hair over 3000 RPM at 80. The tires help, stock-ish 30" tires would be closer to 3300 rpm.

3000 on the highway wasn't that uncommon back in the land before overdrives - but now that we're used to cruising at 2100 RPM, 3000 feels like it's screamin. Doesn't really hurt the engine, per se, but it does affect fuel economy of course.

Interesting, I suppose I don’t normally drive a lot of intestate maybe a 1000 miles a year max. What does she get for gas milage at 80 and 3000rpm?

[truckster]

Originally Posted by 72 k15

At 3000 RPM? can’t imagine that’s decent for the motor or gas milage.

A small block Chevy - any engine, for that matter - should be able to run 3000 RPM all day with no negative effects. Fuel mileage isn't going to be great no matter what RPM you're running, as pushing a brick through the air at 80 MPH takes a lot of energy. If you're considering an overdrive to improve fuel mileage, take a minute to figure out how long it's going to take you to recoup your investment.

[Ptjsk]

Gear Vendors in my '72 Jimmy was definitely one of the best modifications I did to the rig!

350 transmission, 33" tires and 410 gears. Cruises real nice at 75-80mph. Went across Nevada last year and many times was cruising 85-90.

But.....don't even think that you're going to get decent fuel mileage. I don't really know how, but a few times I was just a hair over 12 mpg. Most of the time though I'm between 10-11 mpg.

Pat