6.2 diesel swap, like to hear from people who have done it

[AlaskaMatt]

Yesterdays Salmon haul.

[71-blazer-half-cab]

That's a lot of fish. I find it hard to get forward movement on my projects when I'm out playing. By the way, you blazer looks geat on the beach with the background.

[AlaskaMatt]

350 out. 700r4 in. Need to button up a couple things on the diesel before I test fit. Also need to cut and weld the engine mounts a bit. The crossmember from the donor fits between the rails but the engine mounts (the stands not the rubber part on the block) are too tall. I'll have to cut them down to fit inside the frame rails. Right now it appears that the mounts need only to move forward 1.5". Mount face of both engines to center of engine mounts is the same. The block of the diesel is about an inch longer than the 350. Total forward movement of less than 3".

Next up will be a test fit up and adding the front clip to see how it all fits. Then it's on to radiator and brake systems. And wiring, and and and.
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[RLONG]

I have bought 83 to 85 surbans got 25 mpg loved them why dont they have them anymore but a 350 would be a direct replacement bolt right up same motor supports just better cooling hd

[truckster]

I've thought about the same swap because I love to drive my Blazer but the gas mileage and range issues limit me. The one concern I have is noise. I like to drive around all summer with the top off. I'll be interested to hear how loud the 6.2 is in the Blazer.

[AlaskaMatt]

Originally Posted by truckster

I've thought about the same swap because I love to drive my Blazer but the gas mileage and range issues limit me. The one concern I have is noise. I like to drive around all summer with the top off. I'll be interested to hear how loud the 6.2 is in the Blazer.

Me too. But my 350 was pretty loud with the turbo mufflers so perhaps it won't be very different.

RLong, not sure I follow you. I'm dropping in a 6.2 and 700r4 in place of a 350/350 combo. The mounts on the 6.2 are different than the 350. Location would be the same (without the tranny swap). I hope you were right about the mpg you were getting as that is the whole point of this. I like to go on journey's with my blazer and disappear for a week at a time into less charted territory. Range and efficiency are my goals.

[diesel71]

You will love the conversion, I put a 6.5 in my old 71 two wheel drive truck and it always got over 20mpg and on a 300 mile trip got over 35mpg. And don't worry about power, if you ever get to that point a turbo and upping the fuel will do the trick. My truck was putting out around 500 ft/lbs of torque on a dino. I don't know about a 4wd but on my 2wd the only thing I had to modify was the engine mounts on the truck. I had to cut the top of them and put a flat piece of metal where they were rounded so the manifolds would clear, but it is still very close. Hood clearance was also a thing for me, but with a body lift like yours has it shouldn't be a big deal. And for the return line I just soldered in a nipple on the tank. And the 700 will hold fine, I had one behind mine for a long time. But after you turn it up if you ever do, it NEEDS to be beefed up. I went through 5 after I started putting out as much power as I did. Just FYI.

[AlaskaMatt]

Glad to hear that as I am almost done. Doing the wiring now, then off to the exhaust shop.

I ran into some things here and there and cut the mounts just like you did. 4x4 presents some challenges in the tranny clearance area. But I think I beat them.

Hope to be on the road in a week or so. Ill do a write up once its all done and actually on the road.
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[Kool K5]

Can't wait to see pics!
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[RLONG]

To clear up the 6.2 in the 81 to 87's a 350 was a direct replacement i am pretty sure even the motor mounts were same with exhaust the same . I am sure the older 69-72 are different though. I use to by sale trucks would buy a 6.2 blown cheap buy salvage yard 350 and swap it out worked great most people back then would rather have the 350. I remember the 6.2 transmissions were usually 400 turbo and extra heavy duty cooling made a great swap then gas was cheap.

[brandoncpm]

Love the thread, beginning my 6.2 swap soon. Picked up the donor 83 K20 today and going to swap motor and maybe tranny and transfer case to my 60 K20. MPG is the goal, not drag racing......

[quest]

Hey just came across your questions about the 6.2 diesel and I think it sounds like a great idea.

I can't believe all the neg comments from some people. AND by people that show in their comments that they obviously know absolutely nothing about GM diesels. I don't know why people want to blast your idea when they really don't know what they are talking about.....at all!

I have one main comment to make and that is to become a member thedieselpage.com, if you have not already done that. You will get nothing but positive feedback and support on their forums for your efforts.

I have owned and worked on several of these engines. Compared to the number of diesel engines that were made for GM trucks there have been relatively few failures and generally that is because in many cases people abuse the hell out of them like they would a gas engine. Anyone that is a truck driver or heavy duty mechanic knows that you can't do that.

There have been plenty of these engines that are still going after 500,000 miles because they have been taken care of. Try finding a a chevy/ford/dodge gas engine that has 500,000 on it.

The GM diesels were not built for the abuse of a gas engine, they were built first off for economy and under the right circumstances can get 30-40 mpg in a half ton. But they need to be well cared for. Secondly they are very easy to get parts for and very inexpensive and easy to fix. The most expensive thing you could do to this engine would be to buy a new banks turbo system for it, so shop around for a used one or adapt a 6.5 turbo setup.

I currently drive an 86 GMC with a 88 6.2 diesel that has 250k-300k kilometers on it and I have used it to haul 7500lbs loads with no problem. I have several 6.2 engines in my garage and have toyed with the idea of putting one in my 1965 K20 4x4 Although I am really into the original 292 cyl as well.

The 6.2 diesel can be very well built and powered up considerably for good power and still maintain good economy. Just check out thedieselpage.com . It's a great engine that is fun to build and fun to run, I think they are great.

My 3/4 ton 4x4 gets over 20mpg on the highway and about 15mpg with a big heavy trailer.

[71-blazer-half-cab]

I hear you, I have a 91 diesel van with 280k miles. It is a great rig, I have been pulling my car trailer with it for 12 years and 100k miles. It is not fast up the hills but it cranks out on the flat. It gets 16-17 mpg pulling the trailer and 20 mpg without. The 6.2/6.5 is a great engine in my book.

I do get asked all the time wheither it is the "converted gas engine". You can then tell, they don't know too much about the gm diesel.

Now I just bought another, a 1985 k20 silverado, 6.2, turbo 400, 4.10 gears. It should make a real good winter trailer puller. It is rough but great running gear.

[quest]

Yeah sure do like these motors, dollar for dollar they are the best value. I am very impressed with the towing ability considering the power rating of the engine. And of course I love the sound of it!
Mine is also TH400 with 410's and 31" tires. I have 700R4 I would like to build for it eventually and I think I will go up to 33" tire next time I need tires.

[woodwright]

Did you end up doing manual glows or are you using the stock controller? I converted my 83 K5 to manual control with 60G plugs. I've never plugged it in, just burn the plugs longer when its cold. I've started it down to -10 degrees.

[quest]

Yes, I use a stock controller and I put put a spring loaded button switch on the dash with a solenoid under the hood so that they could not be accidentaly left on. I have the good glow plugs and I can start down to -10 celcius with just plugs but I think these engines will live longer with winter oil and being plugged in below -5 or -10 celcius so I have dual block heaters and I can easily start at -20 and -30.

[jbclassix]

Hey Matt, How is the 6.2 swap coming? I am helping my brother pull his 6.2 for a cummins in his crewcab... and then put the 6.2 in his half ton 2wd! I am a big fan of the 6.2 and 6.5. And I'm not just saying that because I want to go salmon fishing. I think they are great light duty diesel engines. I miss my old 6.5.

[woodwright]

I wish there were more exhaust options. The stock manifolds are ridiculously restrictive, But $600 for headers is a little nuts. I've thought about building a set of block hugger type headers and dual 3" exhaust.

[quest]

Well the next best thing is hummer headers off of Ebay for $50-$100, i bought a pair for $70 I think, haven't used them yet.

[quest]

Also you can easily make an adapter plate for the stock manifolds to connect a 2-3" pipe on each side. A little like a wheel stud adapter.

[71-blazer-half-cab]

A few years back I was at a February swap meet in Lethbridge and the glow plug time basically quit on me. It was a seriously cold day. I could have used an override button. Insteaded I pulled off the dog house (its a van) and jumped the terminals. It worked but what a pain. It starts real good down to about 10 deg F. Lower than doesn't happen too often. The best thing I did to it was I quit buying the Autolite glow plugs. They were lasting me about 1-2 years. I follow some advise and bought the more expensive champion glow plugs and they have lasted a lot longer. This set has been in there about 5 years. I have a couple I think might be bad now, but it still starts great in the winter. A couple of them are really a pain to get to on the van so I'm not ready to check them yet.

[AlaskaMatt]

2 steps forward 3 back. Got it done, I thought, then spent all weekend tying up loose ends and trying to get it cranked up. Bad fuel pump, should have been an easy replacement but I just spend 3 hours on it. Grrrr. Finally got it all to go my way and the fuel line won't thread in. Had to throw in the towel for the day. Busy week ahead and bummed that I won't be testing it out. I won't even get to look at it until Wednesday.
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[chevy88]

I have been following your build and am getting ready to drop in my 6.2 military into a 1968 chev 1/2 ton and would like to fix motor mounts before I drop every thing in. You don't have a picture of how the motor mounts look after you cut and welded up to clear the exhaust manifolds?
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[quest]

Originally Posted by chevy88

I have been following your build and am getting ready to drop in my 6.2 military into a 1968 chev 1/2 ton and would like to fix motor mounts before I drop every thing in. You don't have a picture of how the motor mounts look after you cut and welded up to clear the exhaust manifolds?
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What is it that gets in the way of the manifolds, curious to know?

I thought that because the frames is that same width there should be no problems and also that that engine bay can hold a BBC as well and all the GM V8 motor mounts are the same. I was thinking about putting one of my 6.2 diesels in my 65 GMC so I measured the frame on it and it is the same width as my 86 6.2 diesel truck, I just figured it would all fit.

[AlaskaMatt]

Ill see what I have for photos but I had no clearance issues with the manifolds they cleared without modification. The mounts themselves had to be cut down to fit in the C of the frame. I just cut about an inch off the top and welded flat plate back in. It then bolted back up to the crossmember from the donor.
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