6.2 years to avoid?

[squaredeal91]

I've heard rumors of the first year or 2 of the 6.2s being the best because there supposedly a high nickel content. And they were called orange block 6.2s or something like that?. If that's true I may have an original orange block I'm my 78 k10 that I put in from an early 80s original 6.2 dually truck that pulled a travel trailer across America every year for snow birds was the story i got. Otherwise I think all 6.2s are good and don't get the reputation they deserve.

 

[Big Ray]

Sounds like you have too much fun stuff in your garage

Too much of my Brides crap. And her grown sons crap.
Ready to put my foot down, trying not to do it on their throat...

 

[Big Ray]

I've heard rumors of the first year or 2 of the 6.2s being the best because there supposedly a high nickel content. And they were called orange block 6.2s or something like that?. If that's true I may have an original orange block I'm my 78 k10 that I put in from an early 80s original 6.2 dually truck that pulled a travel trailer across America every year for snow birds was the story i got. Otherwise I think all 6.2s are good and don't get the reputation they deserve.

They were called red blocks, because they were painted red. You are correct, they had a higher nickel content as speced by Detroit Diesel, who designed the engine.
They also speced forged crankshaft that GM cheaped out on and changed to cast, along with cutting the nickel content. All to save a few pennies...
Those two changes changed the 6.2 from what could have been to a almost was.
I may buy an Optimizer if I come across one this Fall, if my 6.2 winds up being beyond saving.

My 6.2 towed fine. Just not fast. Pulled a tandem axle uhaul trailer loaded with furniture after Mom passed. It would get to 60-70, just not in a hurry.

 

[Big Ray]

Just buy the truck you like. Then just look for a spare motor. I’ve got 3 spare 6.2’s and only one 6.2 truck. I am a bit of a parts hoarder and can’t pass up a “deal” though. The fuel system gets expensive but I run a little 2 stroke oil in the fuel to help lubricate the pump. Makes me feel better.

Ben

I always used a fuel treatment. I believe my rubber lines developed leaks, allowing it to suck air.

 

[Thesiger]

Here's a good question. On the older trucks they only have 4 digit odometers, so on a 6.2 that reads "9,000" what are some secondary indicators that would tell you weather the trucks on 209000 or 109000?

 

[squaredeal91]

Here's a good question. On the older trucks they only have 4 digit odometers, so on a 6.2 that reads "9,000" what are some secondary indicators that would tell you weather the trucks on 209000 or 109000?
[/QUOTE
I'm thinking you just have to guess and go off history you may or may not know and body wear tear. Steering wheel wear. Speedo parts wear, rust, Seat wear if it's original etc. and every owner treats things differently. Don't know if one can ever know for sure but most likely you can add 100K to whatever odo shows.

 

[Thesiger]

Probably 109K. She's fairly good looking, even the cruise works. I've never seen that so I assume its gotta be 109K.

 

[Big Ray]

My 90 and my ex's 89 had 6 digit odometers...
Mine says 385xxx...

 

[rwjtexas]

In my understanding when I started looking at Blazer's to purchase the Blazers / Jimmy's in 1982 - 1984 the blocks for the 6.2L were 350 block conversions that had Diesel Heads slapped on them.

In 1985 the 6.2L were changed to true Detroit Diesels. The Issues you may have heard about in the early 80's revolved around the gas block diesels I suppose.

I waited until 1985 to purchase a new Blazer and I still have it .. although the engine was changed out from a "C"to a "V" (Emissions), it still runs good.

You must be registered for see images attach

 

[FBJR]

Well, I have an 86 sub with a 6.2 and hacked on turbo and 4L80. Actually runs pretty well, but redoing the intake and replacing the turbo with a later model (stock).

I had dreams of pushing the motor but no more. I did aquire a early 6.5 motor though (told it smokes) as I was thinking serpentine?

Now I have a 6BT for it and the adapter for a GM tranny.

HOWEVER, I have a NIB Banks manifold I would part ways with if someone is interested??

 

[Grit dog]

Probably 109K. She's fairly good looking, even the cruise works. I've never seen that so I assume its gotta be 109K.

Unless you’re looking for a “valuable” original low miles truck, the odometer reading on any old vehicle is largely irrelevant imo.
There are about 100 more/different clues and things to look at before the odometer reading to determine a vehicle’s condition.

 

[Albrigap]

So then is there a simple fix I could do you proactively stop that? Like I'm looking at a 6.2 with only 106K on it, what reinforcements can I do to get her to 300K?

Replace the head gaskets now.
Drive it 1,000 miles and re-torque the head gaskets.
You will be amazed at how much you turn these bolts.
Then drive it 5,000 miles and do it again.
Keep doing this until you get no additional movement in the bolts.
Now, it will run a long, long, time.
I have taken many 6.2's apart almost with your fingers on the head bolts.
You cannot keep diesels sealed up with loose head bolts.
This is a lot of work but, you asked.
I seen this done on a 350 Olds diesel as well as 6.2 and 6.5's and they ran forever.

 

[Blue Ox]

In my understanding when I started looking at Blazer's to purchase the Blazers / Jimmy's in 1982 - 1984 the blocks for the 6.2L were 350 block conversions that had Diesel Heads slapped on them.

In 1985 the 6.2L were changed to true Detroit Diesels. The Issues you may have heard about in the early 80's revolved around the gas block diesels I suppose.

You must be registered for see images attach

Unfortunately, none of that is true.

 

[Blue Ox]

Replace the head gaskets now.
Drive it 1,000 miles and re-torque the head gaskets.
You will be amazed at how much you turn these bolts.
Then drive it 5,000 miles and do it again.
Keep doing this until you get no additional movement in the bolts.
Now, it will run a long, long, time.
I have taken many 6.2's apart almost with your fingers on the head bolts.
You cannot keep diesels sealed up with loose head bolts.
This is a lot of work but, you asked.
I seen this done on a 350 Olds diesel as well as 6.2 and 6.5's and they ran forever.

How do you retorque Torque To Yield head bolts? Turn them another 90 degrees?

 

[Albrigap]

How do you retorque Torque To Yield head bolts? Turn them another 90 degrees?

I never had torque to yield head bolts. Mainly used ARP studs.