Some general K5 blazer questions

Nissan11

Nissan11

Well-Known Member
Joined
Nov 29, 2005
Location
Marston, NC
Ive been having trouble with my crew cab frontier for about a year now. I think it's about time to throw in the towel and sell it. If I am able to sell it I want to buy another truck that I can wheel, tow a trailer with and work on myself.
I had a k5 when I was in high school and I liked the interior room and simplicity of the 350. I have done some reading on ck5 and a couple other k5 forums but there are just so many opposing opinions. I hope some k5 experts here can help straighten things out.

What I want in a replacement truck:

It will be a secondary vehicle but I want reliability. I want to be able to derive it to work sometimes and make occasional long trips.
I want to have reclining front seats and a back seat.
I want to be able to wheel it.


My specific questions:

6.2 L diesel - lots of mixed reviews about this motor. I've read it is slow but gets good mileage and has adequate power for towing and is pretty reliable. Is that a good overview? How do these motors compare to the gas motors?

Did any k5's come with axles bigger than 12 bolts?

Were certain year k5's considered to be more reliable or in general "better" than others?


I've read 700r4 trannys should be steared clear of. Is that right? What are transmissions that I should look for in a manual truck?


Lastly, will a carbureted motor serve my needs, or do I really need fuel injection?


Thanks!
 
As far a I know the K5 never came with any axle larger than a 12 bolt. As simple as tbi is to work on It be much better than having a carb.
 
I would stay away from the 6.2L diesel.

K5’s came with a 12 bolt rear axle until 1981 I think when it switched to a 10 bolt rear axle. They came with a D44 front axle until 1977 I think when it switched to a 10 bolt.

You are going to want the OD of the 700R4 compared to just a TH350 for long trips you mentioned wanting to take. I think manual transmission K5’s are fairly rare.

I will never own another wheeling rig with a carb. EFI is the only way to go for me offroad.

Lastly, if I was going to buy a K5 for what you are talking about wanting to use it for, I would buy a 1987-1991 model with a 350 EFI gas motor and 700R4 auto tranny. Then, depending on what size tire you want to run, I would hunt down a set of CUCV (D60 front/14 bolt rear) axles that would bolt right in.
 
everybody has hit all the major answers. The 700r4 is a good transmission and is very reliable and there is tons of parts and support for the tranny. It was the only transmission that came with the blazer that has overdrive.

With the 6.2 diesel in the blazer, there is 2 options. Civilian 6.2 and military 6.2 (or J code 6.2) The military blazer 6.2 is stronger and more powerful than the civilian one. The military blazers did not have an overdrive transmission, and as far as I have seen none of the diesel blazers military or civilian came with a manual transmission. Overall the 6.2 is a good simple diesel engine. However there is not alot of mods that can be done to make them into a powerhouse like newer diesel engines. You can put on a banks turbo kit and thats about it. So if you are wanting something you can burn the tires off the 6.2 will not be a good choice for you.

There is really no best years of blazer or years of blazers to stay away from. Really it is a matter of which front end you like and there you go. i am a personal fan of either 90-91 with the 4 headlights or the late 70's with the round headlights, but it is all personal choice.

As far as axles goes it is easy to swap in a 3/4 ton or even one ton axles under these vehicles if you are desire a stronger set up.

Hope it helps
 
Last two answers nailed it.
The 700 can be very reliable if maintained, kept cool, and you dont take the TV cable off thinking its just an old fashioned kick down cable. Cant tell you how many deals Ive scored because of that stupidity.

I would look for an 87+ with the 350 TBI fuel injected. I had an 89 on 35s that would get a legitimate 22 mpg. It was geared too tall for the tires and was slow as hell but got the job done.

The 10bolts are marginally stronger than the 44/12bolts...but not enough to brag about...but as said 60/14 is a direct bolt in.

The 6.2..Im not a fan of simply because parts are a tad more scarce than SBC stuff. And if you ever have to go the route of a rebuild on one...$$$$$$$$.

The wheel base does not lend the K5 to be a good tow choice. But Ive pulled a 19' bass boat behind the aforemention 89 and a cuple others without incident. For a mid size bot, or a lawn mower trailer etc they will be great.

Just dont expect to tow a rig with one.
 
Thank you for the responses. For towing, I was referring to an ATV trailer, maybe 2k lbs total.

Also, for tires I was thinking 35's.


Were the older blazers smaller than newer ones?
 
going no bigger than 35's then the stock axles will be fine. Maybe swap to 3/4 ton's ( they will give you a lower gear set also ) but then you will also need new wheels.
 
What kind of highway speed is the th350 limitted to? Can it cruise at 60 mph?

And back to the 6.2.. Is it just weak and harder to get parts for? Were there any notorious issues with them, like leaking or block cracking? I really don't mind a slow accelerating truck if I can drive it at 60 mph, as long as it is reliable. Is the 350 generally considered to be any more reliable, or is it just easier to get parts for and to work on?
 
for a th350, cruising at 60 should be no problem, depending on gearing/tire combination-just think of running an overdrive trans in "D" on the highway, the ratio is the same, give or take convertor lockup.

for a 6.2, with proper gearing some have acceptable power and awesome mpg, however they have some notorious issues: glow plugs, glow plug control boxes, injection pump and lift pump, if you aren't diesel familiar and wrench your own, these can drive you nuts and broke at the same time.

for a 350, it may use some fuel, depending on carb/tbi, engine tune and condition, but a well-built and tuned 350 is hard to beat for reliable power, parts are fairly cheap and available almost everywhere, almost every professional or shadetree mechanic has worked on dozens of them, small block parts are interchangeable between over 50 years of production(some parts work better than others though)
 
i had the square body suburban. year model 88 and 3/4 ton 4x4. 350 mated to a th400. it had towing gears(4.10) and 30" stock tires. Never had a tach in the truck but there was no way it could do anything over 70. I hit 75 one time passing a slow car one time and thought there was going to be a mass explosion under the hood. Let me tell you no OD sucked. I would look for a 700R4 no doubt. The only other transmission besides the th350 I have seen in those years of blazers and pick ups and suburbans was the manual sm465. No overdrive but bullet proof.
 
I wouldn't call 10 bolt axles and 35" tires 'reliable' for a true wheeling rig. If you keep the axles open and drive with a light foot they will probably be OK.
 
Removable tops were standard on all years up to '91. '69 was the first year of the 4x4 K5. '70 and up offered 2WD. '69 to '75-'76 had removable tops that went all the way to the windshield. Mine never leaked, but gasket (between top and cab) was painted with the rest of the K5. Hope you find one!
 
Nissan11 said:
Did all years have removable tops, and were those prone to leak?
Click to expand...

A good friend of mine owned a 1987 model with the 350/700R4 combo. He bought it in the early 90's and drove it for about 10 yrs. The top never leaked. The motor and transmission held up perfectly. I think it had 170k+ on it when he sold it.
 
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