Should I swap to a 6.2?

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da_raabi

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So I currently have a perfect running 454 in the C30, love every bit of it except the 6 mpg. I have been thinking about throwing in a 6.2 any thoughts? I found one for cheap that might have a blown head gasket (all it says is coolant in the oil) that came out of a 1990 humvee. I could get it for under $400. What do you all think?

My thought is that then I could drop the 454 into my Camaro without having to rebuild it...
 

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6.2 diesels are slow as ****, like really underpowered

what rear gear is in your truck?
 

da_raabi

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4.10s
 

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I have 4.56 gears in my truck and I get absolutly terrible mileage, not 6mpg but not much better, I feel like with 4.10 your mpg is not going to go up as much as your power level is going to go down(if that makes sense)
 

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Hmm. Well that sucks. I was thinking a 6.2 would offset its crappy power output with fuel mileage, but I guess in a billion pound dooley with 4.10s that might not be as possible. Damn...
 

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Hmm. Well that sucks. I was thinking a 6.2 would offset its crappy power output with fuel mileage, but I guess in a billion pound dooley with 4.10s that might not be as possible. Damn...

hey man dont just take my opionion, but I know my old m1009 blazer which weighed like 4500lb with 3.08 gears got like 18-20mpg so take a 6000lb dually with 4.10s and do the math

Im not just one of those people that is a 6.2 diesel hater I was DD my 6.2 with 30k original miles all winter started up every morning without plugging it in! So from experience 6.2 diesel are very reliable and decent fuel mileage in comparison but are just so slow and have literally 0 aftermarket

o and the reason im not driving it anymore is because its getting a cummins:smoke2: had to put that in there
 

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So I did a little math. If I were to get 15 mpg with the 6.2 at current diesel prices I would save $60 per month at my current average distance driven over the 454 gasser at 6mpg. Assuming the swap cost me approximately $600 to do, and who knows how accurate that is, it would take me approximately 10 months to recoup the expense.

Three additional factors:
1: If the fuel mileage is lower, obviously I will have less savings.
2: The farther I drive the more I "save"
3: The more I spend on the swap, the longer it takes to "recoup"

So I dunno. Anybody have a decent estimate of the mileage in a crew dually with a 6.2 so I can be a bit more accurate?
 

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Don't do it! That $400 is gonna turn into $6000 for 170 hp @ 20-25 mpg

I had a 6.2 with coolant in the oil. Simply pulled it out and put in a 350

6.2, th400, 35" tires and 3.42 gears got me 25-30 mpg @ 160 hp

350( Edelbrock 2701 and 1806 carb), 700r4, 33" tires and 3.42 gears give me 25 mpg @ 250+ hp

Don't get me wrong I really liked that little 6.2 but I have heard of guys spending $6000+ just to have the same problem 30-40k later. once those blocks have 400,000k on them there is no guarantee they wont crack at any time, doesn't matter how good the rebuild is. Only other option is a GM 6.5 crate motor for big $s

Not to mention your gonna burn through trannies like you do oil changes.
 

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if you wanna spend some dough why don't you fit a 4l80e into that thing ?
 

marks86

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Don't do it! That $400 is gonna turn into $6000 for 170 hp @ 20-25 mpg

I had a 6.2 with coolant in the oil. Simply pulled it out and put in a 350

6.2, th400, 35" tires and 3.42 gears got me 25-30 mpg @ 160 hp

350( Edelbrock 2701 and 1806 carb), 700r4, 33" tires and 3.42 gears give me 25 mpg @ 250+ hp

Don't get me wrong I really liked that little 6.2 but I have heard of guys spending $6000+ just to have the same problem 30-40k later. once those blocks have 400,000k on them there is no guarantee they wont crack at any time, doesn't matter how good the rebuild is. Only other option is a GM 6.5 crate motor for big $s

Not to mention your gonna burn through trannies like you do oil changes.


$6000 into a 6.2????

we are talking about the 6.2 diesel that detroit made for the chevys in the
80s???
 

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i absolutly see where your coming from with the fuel mileage, I agree

but you can buy a 6.2 diesel with under 40,000 miles for like $500 bucks and I guess if you want to put another $500 into it and reseal every thing, and even have enough for a junkyard turbo kit go ahead, but $6000 is unrelated to a 6.2diesel
 

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I have thought about the 4L80 swap, but I dont want to spend that much. I mean on top of the trans I would need a driveshaft, computer or cheater box and a shifter, etc. I was kind of hoping a diesel would work but it looks like it may not be worth it. Maybe I'll just fix a bunch of other stuff instead...

And I have never seen a junk yard turbo setup around here unfortunately...
 

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To do a proper rebuild: new or reworked heads. proper machining of block new pistons c- rods and possibly even new crank, rings, bearings, main bearing girdle, new oil pump, water pump, j code intake if you don't have one, injection pump, injectors, glow plugs, etc. etc

You could tear that thing down and find cracked heads or block or both. Then what do you got nothing but scrap metal.

If you do the el-cheapo rebuild, more than likely some thing is gonna break.

Even if you do the the full out rebuild something still might break.

They were designed for fuel economy during the low horsepower smog crap era, nothing else.

And , at the end of all that you got 175 hp maybe.

Im just saying I think there are better upgrades to spend money on
 

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I drooled over a day dream of putting a 6.2/6.5 turbo back in my rig but when I factored in all the costs to get a reliable engine and having to spend a couple grand on a transmission for it on top of everything else I said forget that day dream lol

I spent $500 bucks for edelbrock stuff for on top of my 350. I think its much better spent money. Although if it wasn't for that nearly brandnew 700r4/np241 that I pulled out of a 90 burb I would be paying a lot more often for my fuel ups.

only paid a $100 for the tranny and transfer case together put a deep sump pan and cooler on it and it drives like a dream. I actually make up reasons to take it for a spin now
 

marks86

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To do a proper rebuild: new or reworked heads. proper machining of block new pistons c- rods and possibly even new crank, rings, bearings, main bearing girdle, new oil pump, water pump, j code intake if you don't have one, injection pump, injectors, glow plugs, etc. etc

You could tear that thing down and find cracked heads or block or both. Then what do you got nothing but scrap metal.

If you do the el-cheapo rebuild, more than likely some thing is gonna break.

Even if you do the the full out rebuild something still might break.

They were designed for fuel economy during the low horsepower smog crap era, nothing else.

And , at the end of all that you got 175 hp maybe.

Im just saying I think there are better upgrades to spend money on

I guess I see where your coming from.. if you find a 6.2 diesel at the bottom of the ocean and want to rebuild it, its gonna cost 6000 to put new everything in it

All I know is I bought a m1028 with factory posi front with 28k for 1800bucks wasnt started in ten years got it home and started it and have been driving it ever since, I just change the oil and fuel filter and air filter

these 6.2s are pretty stout strong motors, just really slow really really slow
 

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