# Considering a diesel K5 Blazer



## SmugWaffle

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## Tirediron

I think you are probably over building you tank here, a 6BT is heavy and thus requires a DS 60 front, so there you have reduced your diff clearance to less than a stock solid axle K5 with 235 75 15s, 

the 6bt 12 valve inline pump engine is a great choice, if you can get clean fuel

If I was doing a 6BT in a chevy, I would adapt it to a 4L80E (or do a M conversion) And then bolt it to a 205, 

you will need at least 35 inch tires to make up for the bigger diff housing and need to trim the firewall for rocker cover clearance. unless you want to do a hack build and body lift it.

most 6BT trucks had dana 70 rears, you would want to convert it to chevy brakes on the rear, if brakes matter 

Gm trucks have exponentially better stock wiring systems than a dodge except for maybe the alternator.

Unless you are towing I would look for a 6.5T mechanical chevy and just bolt it together and enjoy real fuel economy


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## LincTex

mike_dippert said:


> I think I've read Linc has a 4bt.


I do. It's in a long bed F250 (NP435 4-speed and NP205 TXfer case, D44 front, D60 rear)

Even still, my truck is far too nose heavy for what I would like it to be.

A 6BT in a Blazer? 
What's the weight distribution on that; 85/15? Forget that, it would be hell to drive. The 6.2 liter diesel Blazers were far too nose heavy and a 6BT would make it that much worse.

I have had some "big engine/short wheel base" vehicles in the past, and although they look cool, I'll never do "too nose heavy" ever again.


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## Tirediron

If a 6bt weighs the same as a 6.2/6.5 then It would probably be the choice to go with especially if you moved the fire wall enough to set it back a couple of inches.
A trussed 44 or 10 bolt will handle the weight, and the power unless you get too big on the tires, I have found that 44/ 10s will handle up to 38.5 swampers without axle problems, behind a really healthy 454. 

A 4bt if you can find an inline pump model might work pretty well too, but there is no replacement for displacement. 

GM had a vacuum throttle position valve for the TH400 equipped 6.2 trucks, which should work well for the 4L80(M) conversion. 

I don't know if you plan to pull a trailer with this, in that case a GM 14bolt would be an ideal rear axle, it is stronger than both a dana 60 and 70 and you can put monstrous 1ton single wheel brakes on it or do a disk conversion. But if you are using a W250/350 for a donar it should come with the diff that would work,

Tire rack should lay off the crack, 31 10.50 15 was the sport tire package on the K5, and a truck with decent springs will handle 33s, my sons 90 K5 6.2 truck has 33 12.50R15 baja claws on it , it will buzz the fender a tiny bit on tight turns , but not enough to hurt anything


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## LincTex

mike_dippert said:


> How is it too nose heavy? And what do you consider a good balance?


When it was powered by a 300 cube six, it had good balance. 
The 4BT weighs about 900lbs! It "de-leveled" my truck from when it was 400M powered. I like my truck sitting level....not "slightly nose down".

It is pretty hard on front tires. The whole thing just "feels" really nose heavy. I don't like it. My '93 Ranger with a 5.0 liter is actually better! (hard to believe)



mike_dippert said:


> Do you have any details about your swap posted anywhere?


It's some where in here, from way back in 2007... Haven't been posting there in a while:
http://www.4btswaps.com/forum/forum.php


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## LincTex

Tirediron said:


> If a 6bt weighs the same as a 6.2/6.5 then It would probably be the choice to go with


Not even close. The 6.2/6.5 is about the same weight as a 454. The 6BT fully dressed and filled with liquids is about 1200 lbs.



Tirediron said:


> A 4bt if you can find an inline pump model might work pretty well too,


Nothing wrong with the VE pump. You can turn up the delivery rate (per stroke) just as high as a 6BT VE pump. You'll go over safe EGT's first.



Tirediron said:


> but there is no replacement for displacement.


...except when it just weighs too *damn* much. 
Just because I could shoehorn a 4BT into a Ford Ranger doesn't make it a good, balanced performer.


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## Geek999

I'm planning on sticking with the stock 6.2 GM for my Suburban project. I think going 250-500k miles after rebuild instead of 1,000k after rebuild is adequate for a BOV.


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## Tirediron

LincTex said:


> Not even close. The 6.2/6.5 is about the same weight as a 454. The 6BT fully dressed and filled with liquids is about 1200 lbs.
> 
> I didn't think the 6BT weighed the same as a 6.5, mike said it did in post 4
> 
> Nothing wrong with the VE pump. You can turn up the delivery rate (per stroke) just as high as a 6BT VE pump. You'll go over safe EGT's first.
> 
> the VE pump might bend the dyno needle the same , but the day to day performance is not the same or the durability.
> 
> 
> ...except when it just weighs too *damn* much.
> Just because I could shoehorn a 4BT into a Ford Ranger doesn't make it a good, balanced performer.


If weight didn't count I would run 3406 cats in everything, the engine Case copied when they designed the B series that cummin bought the rights to

Now back to the swap topic 
http://www.thedieselgarage.com/forums/forumdisplay.php?f=67

Have a look through this forum, lots and lots of knowledge there


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## Tirediron

Geek999 said:


> I'm planning on sticking with the stock 6.2 GM for my Suburban project. I think going 250-500k miles after rebuild instead of 1,000k after rebuild is adequate for a BOV.


the 6.2/6.5 family engines that lived past warranty (a lot of that was incorrect driving/ salesman telling people to leave them idle ) are a good engine, a turbo kit on a 6.2 really cleans up their performance and longevity


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## LincTex

Tirediron said:


> the VE pump might bend the dyno needle the same , but the day to day performance is not the same or the durability.


I suppose.... but it isn't worth all the extra cost involved to step up. The inlines are nicer, but I don't see the changes being significant enough to justify the cost.

I bought a used VE pump for my 4BT on ebay for about $200. I thought it would be nice to have a cheap spare (and it paid off!) The inline Bosch pumps are just so much $$$ and the correct injector lines are even harder to find. I think they also use an injector with a different (higher) pop-off pressure, IIRC.

For 95% of those doing a 4BT swap, the VE is more than capable enough to make a nice running vehicle. Very easy to mod and work on as well (also has timing advance built in).


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## Tirediron

I would have to agree on the 4BT that the VE pump is almost the only option, and since most 4BT swaps are for a good run around vehicle with reliability and economy. the problem with rotary distributor pumps in general is being finicky about fuel and the lack of a decent sized timing curve 

the 6BT should have a lot better selection of inline pump parts available due to it's installation in medium duty trucks at least there is here.

the 6.2/6.5 engine blocks got better with development, the electronic pump wasn't very helpful with reliability issues.


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## LincTex

Tirediron said:


> The problem with rotary distributor pumps in general is being finicky about fuel and the lack of a decent sized timing curve


Really? How so? I always run 10% used motor oil in the fuel. Some guys with older 6.2 and 6.9/7.3 IDI engines run a LOT thicker mix than that! I haven't heard of "finicky" fuel problems?

The VE has a centrifugal RPM advance curve, the inline P7100 pump does not the last I heard.


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## Geek999

mike_dippert said:


> So I guess the 6.2 weight I found was for a complete package.
> The 5.9 weight must have been minimal package. In that case, HUGE weight difference. I steered away from the 6.2L b/c of reports of cracking and leaking. I guess I'll start looking at the 6.2L in more depth.
> 
> My FIL just got a 2nd gen Blazer he's flipping. I think I'm going to take a closer look at it to get an idea of space before I put too much effort into planning. A 'burban may end up being a better fit for four after all.


If the 2nd gen Blazer has a diesel already, it sounds like what you're after.


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## Tirediron

LincTex said:


> Really? How so? I always run 10% used motor oil in the fuel. Some guys with older 6.2 and 6.9/7.3 IDI engines run a LOT thicker mix than that! I haven't heard of "finicky" fuel problems?
> 
> The VE has a centrifugal RPM advance curve, the inline P7100 pump does not the last I heard.


From what I have heard the rotary pumps are susceptible to surface coating failure when the ph balance in bio diesel is too acidic, Maybe it is just a theory, the early rotaries didn't seem to have much of an advance, and the rest is just theory, I haven't had a meter on one to know for sure, the last of the 12 valves sure run nice


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## LincTex

Tirediron said:


> From what I have heard the rotary pumps are susceptible to surface coating failure when the ph balance in bio diesel is too acidic,


I'll have to look and see if I can find some numbers


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## Geek999

mike_dippert said:


> Well, after crawling around in the FIL's Blazer, not a fan.
> *Backseat access is more difficult than I expected.
> *I really dislike the glass-in-tailgate design. My FIL had a heck of a time removing the tailgate b/c the window doesn't go down far enough to trip the safety switch.
> *There is zero occupant protection under the removable top.
> *The stock spare tire location is just stupid, and useless with larger tires.
> *Limited interior cargo space when using backseat.
> 
> I do like all the space in the engine bay, and the spacious front seats.


So, scratch that choice. My Suburban project has cargo doors, eliminating one issue and simply being larger eliminates the interior cargo issue. Some of the rest still applies. These are 30-40 year old designs.

Personally I would like a brand new Escalade ESV that was absolutely EMP proof and ran on diesel, with about 4 inches of lift and 100 gallon fuel capacity. Of course there is no such animal, and I couldn't afford it if it existed, so I am compromising on a 1984 Suburban project car with rusty doors. Gotta start somewhere.


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## Geek999

There are a couple of us with Suburbans, or Suburban projects, or in my case a rusted heap that was once a Suburban. You're still looking at an old design, but it does seem to address some of the things you didn't like about the Blazer. The only thing larger is an Excursion, unless you go out of the SUV realm, but that is going to have modern electronics. I'm not sure how important that is to you.

In my case I don't have the electronics expertise to know what holds up to an EMP. I like old cars anyhow, so I figured one antique in the garage would be fun and I settled on the Suburban project.

I'll probably have it finished when I am 110.


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## LincTex

Geek999 said:


> In my case I don't have the electronics expertise to know what holds up to an EMP.


Just buy a few spares of the things you will need.

I don't think a spare starter is necessary (it's pretty stout), but a spare alternator and spare distributor don't take up a lot of space.

If you know how to take those two components apart, and have a PROPER tool kit - - then you can save even MORE space, since the "electronic" guts from a GM alternator and an HEI ignition module will all fit inside an empty Marlboro 100's box (and it's foil lined, too!)


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## Geek999

LincTex said:


> Just buy a few spares of the things you will need.
> 
> I don't think a spare starter is necessary (it's pretty stout), but a spare alternator and spare distributor don't take up a lot of space.
> 
> If you know how to take those two components apart, and have a PROPER tool kit - - then you can save even MORE space, since the "electronic" guts from a GM alternator and an HEI ignition module will all fit inside an empty Marlboro 100's box (and it's foil lined, too!)


The problem is that as newer designs have incorporated an ever expanding list of electronics, and hence necessary spares, hence one old Suburban in the family fleet. The rest will be fine in anything short of an EMP.


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## Tirediron

mike_dippert said:


> I think a 2500 Suburban with cargo doors is the ticket. I can add a swing out tire carrier with cargo doors (I HATE them with tailgates/hatches).
> Four doors for easy access.
> Longer cargo area. Space for a permanent fuel cell or two.
> Full metal roof. Could add a roof rack if I want.
> D60 and 14b will hold up to some serious abuse.
> 
> I just need to find one relatively rust free, probably from the desert. My FIL's K5 is rusted through in a lot of places. He has a pile of replacement panels sitting in his shop. Majority of the underside has bad rust too.


' 84 and newer had a better floor pan, in the pickup cab anyway, subs and K5 should have got the upgrade to


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## Tirediron

*new spin on the GM suv*

IF I was building a GM based BOV from a SUV, I would use the 93 - 99 platform and just change the transmission valve body to mechanical and put in a HEI or point ignition and carb if you are concerned about EMP. or swap in a 6.2/6.5, they were available in some 2 door models,


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## HamiltonFelix

I still remember a nice 1994 6.5 turbo diesel two door Blazer/Tahoe that I had to pass up in 1996, having just bought a 1996 Suburban. That generation had a better, wider back seat, and the diesel would have been great. But if you plan to carry much, and you aren't too worried about fitting into tight places, a K2500 Suburban (with the "barn doors") is hard to beat.


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## Tirediron

We have a bit of a collection of Yukons and Tahoes, (And duallies) one '97 with 435000KM on it that hasn't had many repairs at all. GMT400 series trucks are well built


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## LincTex

Geek999 said:


> hence one old Suburban in the family fleet.


That's the only one I can help you with.


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