I want to build a driver K10

[franken]

Most 73+ rear ends have a different (wider) spring spacing and different shock mount than the earlier trucks. In front, 71-87 (later in Suburbans, crewcabs and maybe blazers) are the same or close.
NP203s for a doubler are sort of hard to come by at least near me. Look into a range box using an NP231 (or others) planetary gear set, NP205 and later model NV4500 for the killer setup that includes a super low low range (plus 2 less low lows), and overdrive. Later NV4500s have 5.6 1st compared to the earlier ones w/ 6.3.

[JJ55chevy]

the springs are about 43 1/2" eye to eye, back in high school I learned the hard way bout some of the things on these trucks pouring every dime into my 72 blazer....like the time I took my life savings and one u bolt to the shop to get new 4 u bolts made just to find out that I grabbed the one that was different than the other three...I will start posting picture today...I have another surprise twist that I will post later today too

[JJ55chevy]

ok folks, I am getting a little side tracked on this little project, first of all, I need to figure out how to post pictures on here....I took the box, front clip and cab off the 3/4 ton frame in the great outdoors of Minnesota today. I like the stance of the 3/4 ton as is with the 3 leaf front end and heavier rear springs. I mentioned in an earlier post about a new twist, I found another donor truck for the frame, it is a 72 Chevy 1/2 ton 350/350/NP205 that I am buying for $900. Since I can never focus on anything I got to thinking, I might take the body off my DD 69 GMC and put it on the 3/4 ton 4x4 frame, drop in the motor and add a set of tires and voila' new life for my old truck......then I will get back on track and take the newly acquired 1/2 ton and build my original plan minted out 72 4x4 (after I find a body)....that's the newest plan......on a side note: the 700r4 turned out to be a 4l80E so I am back to looking for a transmission....maybe the guy at the shop that I plan on using to build on will have one and take the 4l80 for a core.

[mrein3]

Originally Posted by JJ55chevy

I went and got the '70 GMC 3/4 ton, unfortunately I did not know the year of it before I committed so it has the drum brakes in the front...I will worry about the ales later since they are easy to swap out at any time...right now I want to figure out how to get the 700r4 hooked up to the 205...right now it has a turbo 350 bolted to it so I just need to find out what adapter I need.....anyone jnoe off hand what and where I can get the spacer?.....is there anything else besides the spacer that I will need? tomorrow I am going to start stripping the body off the frame to make for a clean slate

Originally Posted by JJ55chevy

ok folks, I am getting a little side tracked on this little project, first of all, I need to figure out how to post pictures on here....I took the box, front clip and cab off the 3/4 ton frame in the great outdoors of Minnesota today. I like the stance of the 3/4 ton as is with the 3 leaf front end and heavier rear springs. I mentioned in an earlier post about a new twist, I found another donor truck for the frame, it is a 72 Chevy 1/2 ton 350/350/NP205 that I am buying for $900. Since I can never focus on anything I got to thinking, I might take the body off my DD 69 GMC and put it on the 3/4 ton 4x4 frame, drop in the motor and add a set of tires and voila' new life for my old truck......then I will get back on track and take the newly acquired 1/2 ton and build my original plan minted out 72 4x4 (after I find a body)....that's the newest plan......on a side note: the 700r4 turned out to be a 4l80E so I am back to looking for a transmission....maybe the guy at the shop that I plan on using to build on will have one and take the 4l80 for a core.

OK. I'm back in town and on a keyboard. What I want to say I didn't want to type in to my ipod phone.

I've had a 4x4 since 1994. When I got it the truck was a 1970 2wd non-AC cab and box on a 1971 1/2 ton 4x4 chassis with a 3-speed manual coupled to a NP205 powered by a tired, low oil pressure 350 out of a 1978 truck application. All stock parts but it was a mutt.

For me, the ideal 4x4 would be:
1972 3/4 ton chassis (disc brakes, heavier rear axel)
V8 engine
700r4 transmission
AC cab.

First of all, if you are building a truck, keep up on your paper work. I had copies of all the titles from the state of Wyoming where some cowboy built this truck. I brought it all to the Minnesota DMV. It all checked out so I was issued a MN VIN tag which was affixed to the B pillar by a DMV guy. You want a truck you can drive, license, and perhaps sell one day.

I would rather have 3/4 ton set of axles because I do use my truck as a truck. With the 1/2 ton rear I have to greatly limit what I haul in the bed. I'm limited to about 1000 pounds of crap. Any more is dangerous to myself and others on the road. Don't make your stupidity somebody else's problem by overloading a truck.

The 3-speed I had in the truck gave me the best mileage. On a good day I could get 13 mpg. I rarely had a good day because I'm usually towing something. Towing I got around 10 mpg. Now with the th350 and fresh 383 I get 10 on a good day. Sometimes 11 if I have a tail wind and I baby it all along the way and go through a whole tank without towing. 9 is normal pulling stuff.

The 3-speed manual was great in that it was much easier to shift the transfer case. You could simply push in the clutch while rolling, shift the t-case, and re-engage the clutch. With the th350 you have to come to a full stop and put the truck in park to shift the t-case. You'd be surprised how handy that 4Lo is in 2wd (front hubs not locked) for extra low gear crawling.

I just couldn't keep it from jamming. I did all the "fixes" I've read about on this forum. New bushings, adjusted shift levers, I even paid a shop to "adjust" it. But no matter what I did it would jam at the worst time. Usually the boat ramp or in rush hour traffic.

I went with the th350 because I couldn't make the numbers work. No matter how you calculate it, that 700r4 would NOT pay for itself in fuel savings. Even at $4/gallon gas. Now that we are back to $2 gas forget about it.

That being said I wish I spent the extra for the new output shaft and more expensive 700r4 rebuild. The simple reason is for lower rpms on the freeway. At 70mpg my 383 is screaming bloody murder at 3200 rpms. I rarely drive it without a boat or something attached on the freeway so I'd be in 3rd anyways but maybe I would use it more on the freeway with a better tranny in there.

I converted the cab to be a stock AC cab. Save yourself the trouble and start with an AC cab. AC not only keeps you cooler on hot summer days it also clears the windows on rainy and/or foggy days. AC air is dried air. Before the switch to AC I had trouble keeping the windows clear. And I swear the heater is hotter in the AC system over the old non-AC system.

Don't be worried about that closed knuckle front axle in the one you bought. I've never done it but I understand converting it to disc brakes and open knuckle is as easy as finding any 3/4 ton 1971 - 1987 front axle. I would do that verses trying to find a matching gear ratio front axle. You do have to have matching ratios or something will break the first time you try 4wd.

The part you need for your 700r4 is made by advanced adapters.
http://www.advanceadapters.com/produ...placing-th350/

There is a spacer somebody makes and sells but using the above part you already are adding 1-7/8" of length to the drive line. I don't know what that spacer adds on top of that.

You can move the engine cradle up that far and leave the drive shafts alone. The other alternative is to move the transfer case/transmission cross member back and cut the rear and lengthen the front shaft.

You can get lower highway rpms with taller tires or 3.07 axles but then you can't pull stuff as good.

I think that just about covers my thoughts on 40 year old 4x4s.

[67 chevelle]

with 33 inch tall tires ,410s should be good , 373s would be to tall , 456s would work also the overdive would be nice with 456s , you would have great off the line pulling power

[JJ55chevy]

I'm liken the input here.....looks like I am going to build two trucks and I plan to get them done by springtime...here's my plan:

truck #1 use the 70 3/4 ton rolling chassis that I just got, the axles are the open knuckle but like I said, they are drum brakes, just have to find out what it will take to convert them, the turbo 350 and NP 205 are still in place as is the rear drive shaft. it already has power steering and power brakes and all the parts are there. I will just take the body off my daily driver 69 GMC and drop that on the 3/4t 4x4 along with the motor and buy new exhaust...easy peasy and it will not break the bank til I go for the tires, that should make a fairly decent work horse for pulling my little car trailer. the frame under my 69 is a 72 c10 coil spring 1/2 ton that rides like a charm so I might regain some of my losses on that.

truck #2 I am buying a 1972 K10 with a 350/350/NP205. I will strip the body off that and buy a mint 71-72 truck(has to be that grill style, luv 'em) that I can use on my frame...either AC or not, seems they want an extra $1000-$1500 for an ac truck around here and for that price I will just buy a brand new aftermarket kit.

I will use the 1/2 ton chassis with my 6" lift kit, I will buy a new 350 from jegs, buy a rebuilt 700r4 with the aftermarket output shaft to go into the NP205,I want to just leave the transfer case in the stock location and move the engine forward if the transmission is longer(correct me if I am wrong on this idea), have the driveshafts modified to length and play it by ear on what gears to go with.....I am leaning towards 35" tires with 373 gears. I would use this truck for cruise nights, going to work (7 miles one way) and occasionally pulling a small trailer.

[57taskforce]

One question??? Why the heck would you ditch a 4l80e for a 700r???? The 4l80e is a turbo 400 with overdrive. Sure you'll need a stand alone computer to run it and a turbo 400 np205 or a modified turbo 350 205. The strength of the 4l80 is way worth the extra money in my book. If it were me id ditch the 700r. I have one of each. 4l80e wins in my vote every time. I know some people love the 700r to death and that's fine, but you've got to build one to last in a 4x4 especially a lifted one. I guess if your already gonna build the 700r than it wouldn't be a huge deal but I personally would rather have the 4l80e. I look forward to following this thread. I wish I could find cheap 4x4 trucks around here. You are a lucky soul!

[JJ55chevy]

when I bought the transmission I was buying an engine from the guy and didn't do any research when I saw it laying there and he said it was a 700r4. so I bought it with future plans to put overdrive in my truck because it was only 100 bucks and he claimed it worked when he pulled it from the van, it came with the torque converter and flywheel. With that being said I would have to say if I can not tell the difference between a 700r4 and a 4l80 I better stick with the basics, not to mention I have to draw the line somewhere. I just plan on building a street driven 1/2 ton 4 wheel drive that is reliable and parts are readily available. I am in my comfort zone with these trucks, like I always say, if you shop around enough you can replace any part on these things for $100. That is why I am building a truck for 10 grand as opposed to buying a late model truck for 10 grand that will have 200K miles on borrowed time.

[Nitis]

I think I would investigate an LS swap at this point. Then you could utilize your 4l80e. Up north you should be able to get one cheap enough to justify the incidental costs.

Sure you'll need a crossmember swap but you're doing a 6" suspension lift so clearance issues are null. You're going to spend close to $2k on a descent crate motor not counting the intake and accessories.

[MARKDTN]

Mileage does not have to be dismal. I have a '83 K20 that I have had since '91. It had a 350/700R4/3.42 gears. It got 14.5 city and maybe 17 highway. When a cam lobe went down, I swapped in a bone stock '91 Corvette Tuned Port engine and now my mileage is more like 17 city and a bit over 20 highway. It tows trailers so much better than the carbed one! I am running about a 30" tire. If I was doing it today, it would be an LS engine. 5.3 LS with 4L60E and a transfer case should not be too hard to come by now.

[57taskforce]

What I was trying to say is that the 4l80e I'm my 98 k2500 has 200000 on It, 100000 of which it has pushed 35's. It's a factory 454 truck. Both engine and trans are original I've owned it over ten years. The 700r is known to be weak in lifted 4x4 applications. Sure you can build one up but I'm still not convinced you could get 200,000+ miles from one with big tires and no rebuilds. You'll definitely have to re gear if you go with the 700r. Longevity wise The 4l80e will be fine with 3:73 or numerically Lower gears. Like said above for the money you'd spend on rebuilding the 700r and getting a crate motor, an Ls swap or even a late 90s vortec swap may make more sense and allow you to run the trans you have. If I were close to you I'd rip the 1,000 mile corvette spec 4x4 700r out of my '57 and trade heads up for the 4l80e right now.

[JJ55chevy]

LS1
4L80E
computer

you guys priced me right out of this thread

[Nitis]

How do you figure? You said you were going to buy a crate motor? You going to be into that a minimum of 2k

Should be able to get a drop out engine for under a grand especially up north where you are don't get an LS1 just a truck 5.3 and wire it yourself.

Do what you want by all means just offering suggestion

[JJ55chevy]

a brand new 350 engine from Jegs is $1509 delivered. That would be compatible with my existing intake, carb, HEI, exhaust manifolds etc....I can't see the advantage of a used LS motor and all the added costs.

[Nitis]

Im not a mechanic nor do I claim to know all there is to know about engines but I do know that that $1500 crate motor will run just fine but will leave a lot to be desired

you just dont get much bang for your buck. Now if all you want to do is put around town great.

I think you would surprise yourself if you actually sat down and put a parts list together and priced it out especially if you can get a smoking deal on an engine. I was talking with a guy in michigan recently who said he could get them all day long for $500-$700

SO lets say engine $700
Crossmember $300
fuel tank /lines/pump $300

Dont count adapter for trans since you are talking Overdrive anyway right?

Maybe 300-400 for wiring if you dont do it your self

Kind of a wash in my eyes.

you are obviously wanting the best fuel economy reasonably possible hence the overdrive trans. That isnt going to happen with that crate motor. And just the driveability of the LS. And no waiting for it to warm up in the winter.

Yes I know there are intangeables I over looked but you really arent that far apart if you really look at it.

[Nitis]

heck even if you use a 4.8 you will be worlds ahead of that carbed 350 and you can always swap in anything you want later on up to a 6.0

[57taskforce]

Not to mention that a lot of people are going way past 200,000 on stock Ls motors, so a used one isn't a horribly big risk in my opinion. Even of you tore it down a bit to check bearings and replace gaskets you wouldn't be out much money only a few hours of time.

[WhiteWhale]

I used the 260hp crate for my burb and since I HATE automatics I looked into the 4l80 and 700r4 as I plan on some long trips now and then and wanted a bit more mpg. The main reason I stayed with the gen I engine and th350 was plain simplicity. As long as the trans didnt fail I could pretty much limp home with some mickey mouse fixes especially in the dirt. If a ECU failed you are pretty much dead in the water.

If I was building a street queen commuter I would have gone vortec/4l80e with 3.73 and increased the tow miles on my AAA especially if using junkyard parts.

[JJ55chevy]

I think I'd rather plunk down the 1500, spend about a day of installing it and drive it the next week as opposed to spending hours on the internet finding out what will work with which parts, shopping the boneyards and craigslist hoping to find some useable parts, adding in a bunch of electronics that will need programming, I am sure my choice of transmission would not be good enough so I would have to upgrade that too......since I am that far into it I might as well get that LS motor rebuilt since who knows how many miles are on it....them dana 44's will never hold up to the nitros system that it needed, better get some good tires to go with the package and there I am...I will have my reliable truck that I just wanted to tool around town with for under my $10,000 budget....or I can just go back to my original plan and go with a 350/700r4/NP205 for a driver and go wild with my 68 Vette if I get the urge.....lol......I just want to build a simple truck out of tried and true combinations that snap together in my spare time....for my purposes the time spent on an LS conversion would be a waste of time.

[JJ55chevy]

Originally Posted by WhiteWhale

I used the 260hp crate for my burb and since I HATE automatics I looked into the 4l80 and 700r4 as I plan on some long trips now and then and wanted a bit more mpg. The main reason I stayed with the gen I engine and th350 was plain simplicity. As long as the trans didnt fail I could pretty much limp home with some mickey mouse fixes especially in the dirt. If a ECU failed you are pretty much dead in the water.

If I was building a street queen commuter I would have gone vortec/4l80e with 3.73 and increased the tow miles on my AAA especially if using junkyard parts.

that is exactly what I am getting at. simple easily available parts that give you a warning before they go bad.

[Nitis]

Fair enough just was offering an option!

[WhiteWhale]

Ive had several DD trucks in the past and my favorite was my 74 K10 SWB.

454 oval port HEI (stock)
SM465 trans
NP205 t/c
D44/12 bolt with 3.73
33 inch mud terrains
4 inch lift

That thing took me EVERYWHERE both street and local black diamond trails even without posi/lockers. It smoked the tires easily and towed anything I wanted but did only get 8mpg loaded or empty. Only required basic maintenance and the occasional U joint. I put over 40K HARD miles on it and it never let me down while friends with newer shinier trucks seemed to have issues that were expensive to fix. For me it was the best $1K truck ever. I wanted an overdrive 5831 brownie box for a bit better mpg but could never find one under $1500 so I just bit the gas bullet (which was only $1.25 a gallon at the time).

KISS and enjoy

[JJ55chevy]

Originally Posted by Nitis

Fair enough just was offering an option!

duly noted

[JJ55chevy]

Originally Posted by WhiteWhale

Ive had several DD trucks in the past and my favorite was my 74 K10 SWB.

454 oval port HEI (stock)
SM465 trans
NP205 t/c
D44/12 bolt with 3.73
33 inch mud terrains
4 inch lift

That thing took me EVERYWHERE both street and local black diamond trails even without posi/lockers. It smoked the tires easily and towed anything I wanted but did only get 8mpg loaded or empty. Only required basic maintenance and the occasional U joint. I put over 40K HARD miles on it and it never let me down while friends with newer shinier trucks seemed to have issues that were expensive to fix. For me it was the best $1K truck ever. I wanted an overdrive 5831 brownie box for a bit better mpg but could never find one under $1500 so I just bit the gas bullet (which was only $1.25 a gallon at the time).

KISS and enjoy

simple is a good thing...I save the complications for the vette

[57taskforce]

Originally Posted by JJ55chevy

I think I'd rather plunk down the 1500, spend about a day of installing it and drive it the next week as opposed to spending hours on the internet finding out what will work with which parts, shopping the boneyards and craigslist hoping to find some useable parts, adding in a bunch of electronics that will need programming, I am sure my choice of transmission would not be good enough so I would have to upgrade that too......since I am that far into it I might as well get that LS motor rebuilt since who knows how many miles are on it....them dana 44's will never hold up to the nitros system that it needed, better get some good tires to go with the package and there I am...I will have my reliable truck that I just wanted to tool around town with for under my $10,000 budget....or I can just go back to my original plan and go with a 350/700r4/NP205 for a driver and go wild with my 68 Vette if I get the urge.....lol......I just want to build a simple truck out of tried and true combinations that snap together in my spare time....for my purposes the time spent on an LS conversion would be a waste of time.

All you had to say was you were trying to steer clear of efi and half the posts in this thread would have been omitted. Just saying. I have got a few carbed vehicles and I don't normally put "4 barrel" and "good fuel economy" in the same sentence. Hence why I was suggesting efi as well as the benefit of the 4l80e. Don't get me wrong I've got nothing against simple. My 3100 is carbed and simple as simple gets. The only thing I plan to eventually change in the whole truck is the 700r. It just helps everyone here if you say upfront I don't want something in particular so we know what you've got in mind a little better that's all. Good luck on your build I will keep an eye on it.