1990 k5 Help

[sdjohn99]

I picked up a nice 90 K5 a few months back. No rust and it has all new/rebuilt exhaust, drivetrain, transmission. When the drivetrain work was done the stock rear was replaced with a posi-trac. I'd like to know what you guys think are the best bang for your buck mods to make this a great expo truck. I live in southern Nevada and we have 1000's miles of dirt roads with lots of great stuff to see.

 

[Sock Puppet]

What are your plans/goals for the Blazer? Which engine/tranny/gear ratio?

 

[sdjohn99]

Plans etc.

What are your plans/goals for the Blazer? Which engine/tranny/gear ratio?

I plan to use it as a daily driver and for camping/hunting/fishing trips in Nevada/southern Utah. Like to be able to handle moderate trails. No plans for anything extreme. Thinking of rear bumper with spare tire, jack, Jerry cans etc. , maybe air compressor, roof rack and extra lights. Stock engine,transmission and gearing. 265/75/r16

 

[redthies]

Which "stock" engine,transmission and gear ratios? 305, 350, 6.2? Auto, 4spd? 3.73, 4.10 etc... Either way, a mild lift, some 285-75-16 or 255-85-16's in a decent aggressive allterrain tire, some recovery gear, some spare bits and some camping gear, followed by some time in the wilds! That's the way forward...

 

[washington taco]

I had an "84" you can trim the front fenders in the back and run 33/12.5 all day long. Then go out and explore find out your needs then do the mods you want/require. Take the back seat out and you have a comfertable sleep area!

 

[sdjohn99]

Thanks for the responses

Which "stock" engine,transmission and gear ratios? 305, 350, 6.2? Auto, 4spd? 3.73, 4.10 etc... Either way, a mild lift, some 285-75-16 or 255-85-16's in a decent aggressive allterrain tire, some recovery gear, some spare bits and some camping gear, followed by some time in the wilds! That's the way forward...

It's a 350 automatic. I'm not sure on the ratio. When I replaced the drive train, my friend (who is a mechanic) had posi-trac rear off that came off of a Nevada Department of Wildlife truck and we swapped out the rear at the same time. I think we put in 4:10 but I'll have to check. Does anyone have any suggestions on a bumper? I'd like to get the spare out of the back and have storage for gas/water (gas and water can be hard to come by even on paved roads through central Nevada). Also, what are the thoughts on going with a 285/75/16 as opposed to a 255/85/16? I know both are approx. 33" (which is 2" taller than what I have now) and the 285/75 is wider than my current 265/75 and the 255/85 is narrower. I'd like to put off doing a lift in the near term until I get this truck out and about to see if I really want/need to lift it. Will the 255's be easier to fit with less trimming? What are the advantages/disadvantages of the wider or narrower tire? I'll post some interior pictures soon.

 

[redthies]

255s are narrower. The 285s would be my choice for your rig. You can run them with stock suspension too. If you have 15" rims, 33-10.50-15 is the equivalent to the 285. I suggested the 16" sizes because of the load range D.
This will be better for packing all the gear you may eventually load in the truck. BF Goodrich has a great tire size chart for their ATs and MTs that gives you all the size and load info on one page. You won't have to worry about tire size vs gear ratio with the 350 auto...

 

[sdjohn99]

I went to talk to a local fabricator today to get some bumper ideas. I've attached a pic of a swing away design that I think looks good. Anyone have pictures of a swing away design that looks good and works well? I'd like to carry a spare, hi lift, and at least a couple cans. I'm in Las Vegas so if anyone knows of a good fabricator out here let me know.

 

[sdjohn99]

Here's the current bumper.

 

[Metcalf]

That is a nice looking blazer! Looks very clean and simple...

I would also keep it looking nice and simple. It's a bit of a shame that you have just redone the drivetrain. Not matter how much I try, I just can't love the c-clip rear axles...be it 10-bolt or 12-bolt. I'm a big fan of swapping in a 14-bolt just for the full floating axles. Its also super cheap to do. Bolting 8-lug stuff on the front is pretty dang easy if you don't want to install a Dana 60. I think for most vehicles the D44 is just fine if you are not going to run a 37"+ tire. You could also look around for a rear full floating axle it, I think Warn made one at one time. That would be a GREAT investment.

Adding the biggest deepest pan you can to the automatic transmission would be good. Your transmission will be much more happy. The extra fluid really adds some heat capacity and durability.

As far as tires. I don't even think I could bring myself to cut the fenders on a truck that nice. A set of fiberglass 'baja' style fenders could gain you a TON of room in front, but in the rear adding fiberglas 'bedsides' is a very serious thing with lots of cutting. So, without cutting or new fenders you are going to be limited to narrower 255 or 285s at close to stock height. If you where REALLY careful with wheel selection you MIGHT be able to squeeze a set of 315/75r16s on it. It would be pretty dang tight and require a carful choice of backspacing.

My standard advise is NOT to bolt stuff to the back, outside, or top of any off-road vehicle ( or any vehicle ). It just affects vehicle dynamics too much for me. I would leave the space tire inside even though it takes up some room, depending on the tire size you might be able to find a narrower spare tire to gain a little room. For extra fuel I would look into a replacement fuel tank to keep the weight as low and forward as possible.

Hope this helps, good luck with your project.

 

[sdjohn99]

That is a nice looking blazer! Looks very clean and simple...

I would also keep it looking nice and simple. It's a bit of a shame that you have just redone the drivetrain. Not matter how much I try, I just can't love the c-clip rear axles...be it 10-bolt or 12-bolt. I'm a big fan of swapping in a 14-bolt just for the full floating axles. Its also super cheap to do. Bolting 8-lug stuff on the front is pretty dang easy if you don't want to install a Dana 60. I think for most vehicles the D44 is just fine if you are not going to run a 37"+ tire. You could also look around for a rear full floating axle it, I think Warn made one at one time. That would be a GREAT investment.

Adding the biggest deepest pan you can to the automatic transmission would be good. Your transmission will be much more happy. The extra fluid really adds some heat capacity and durability.

As far as tires. I don't even think I could bring myself to cut the fenders on a truck that nice. A set of fiberglass 'baja' style fenders could gain you a TON of room in front, but in the rear adding fiberglas 'bedsides' is a very serious thing with lots of cutting. So, without cutting or new fenders you are going to be limited to narrower 255 or 285s at close to stock height. If you where REALLY careful with wheel selection you MIGHT be able to squeeze a set of 315/75r16s on it. It would be pretty dang tight and require a carful choice of backspacing.

My standard advise is NOT to bolt stuff to the back, outside, or top of any off-road vehicle ( or any vehicle ). It just affects vehicle dynamics too much for me. I would leave the space tire inside even though it takes up some room, depending on the tire size you might be able to find a narrower spare tire to gain a little room. For extra fuel I would look into a replacement fuel tank to keep the weight as low and forward as possible.

Hope this helps, good luck with your project.

Thanks for the thoughtful advice. I think I'm sold on going with 285/75/16 and leaving it stock height and not trimming. The fuel tank replacement is a great idea that I think I'll go with as well. Given that this truck is a daily driver, anything I can do to increase fuel efficiency is a good thing. Would you go with a replacement bumper? I'd like to get some more clearance in back and be able to have some secure attachment points for recovery. Maybe something like this without the brackets for the swing out.

 

[Metcalf]

it all depends on what you are after. I like the look of the stock bumpers, and its nice that they come around the corners some. Most fabricated bumpers look like fabricated bumpers, its a bummer that common people can't afford to have a bumper pressed out of something like 1/4" material. I think that would look the best. One thought would be to have the factory bumper sandblasted to get rid of the chrome, then have the inside of the bumper reinforced where you can't see it, and finally have the bumper chromed to look stock. That would be trick! I have been wanting to do that for a number of years.

The same idea could be used front or rear.

In the front the GM solid axles are very lucky to have the room to mount a winch hidden mostly behind the front bumper. I love this look and I think it is very practical for most people. I don't think its worth adding 100+ pounds in bumper and grill guard to mount a winch. I can dig up some pics if you want.

Go against the grain...build something new and original!

 

[1leg]

You will get better MPG with the 255s. I think they would fit without any mods.

Your truck should have come stock with the 700R4 overdrive automatic transmission. If you replaced it with the th350 and still have it let me know.

 

[sdjohn99]

Pictures would be awesome. Thanks for all the help.

 

[sdjohn99]

You will get better MPG with the 255s. I think they would fit without any mods.

Your truck should have come stock with the 700R4 overdrive automatic transmission. If you replaced it with the th350 and still have it let me know.

extra MPG is always good.