i'm new, and my build hasn't been as i wanted...

[79 jimmy]

this is my 79 gmc jimmy, when i got it...


umm, i hated these...

so i fixed...
33 1250 15 wrangler dura tracks, and a VERY TEMPERARY 3 inch block lift all around... even front, yes i know, stupid.


then i got a "four inch lift" from rough country, they sent 6 inch springs tho...
so i had a lean,


fixed that by rearching rear springs, and adding a leaf, that with 3 inch blocks puts it good. =]

[jrdv]

Always liked those older jimmy's. My best friend in high school had one that we took on skiing trips. Good times!
Don't let the set backs get you down. The more work you do on the truck, the better mechanic you become. The only way to learn is to do it yourself. I guess that is part of owning an old truck!

Have fun and keep up the good work. I think it looks good!

John

[ghettoluxury]

Looks alot better and you learned to work through your problems as you go.

[Hoods69BadBowTie]

Sweet looking Jimmy looks good so far just need some bigger tires now haha Have fun and keep up the good work!
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[79 jimmy]

thanks all, i know about set backs and working thru them, my first truck was a 1966 small window c10 longbed, 250 inline6 with 4spd granny. i restored and replaced every panel on it while in high school exept the cab. then had to sell it cause my folks bought a house with less parking space, and i was starting college. that truck tought me soooo much about set backs, crappy body, and in the middle of fixing that, the motor blew, (as my dd and as a high school student) that kicked my ass, but i rebiult and learned them 6's like the back of my hand. =] so it made me a better mechanic =] but this jimmy is teaching my new lessons.

and bigger tires (35's) will happen when money alows. lol

[ncgamedog]

Sorry to hear abt the setbacks. How about I just make it super simple for ya in one post? Sound good?

Dude 73-87 K5's have the simplest and probably cheapest build formula on the planet! But, If you dont know it I could see where there could be a ton of growing pains.

Assuming you have a good running, mechanically sound K5 to start with...

First, Suspension.
FORGET what you've learned about 1980's tech, the idea of "lift kits", and what you read in the back of a 4wd rag.

The best 4" "lift kit" on the market is is less than $200. This is the tried and true way to get an APPROPRIATE amount of suspension travel that allows for larger tires and better ride comfort.

Take the stock rear 52" long springs, remove the overload spring, and install them in the front. This requires that you move the front spring mount to a new position in front of the body mount. Don't worry, most of the holes are already drilled for you and there is NO WAY to screw it up. Simply remove the rivets holding on the mount and its upper 90* support bracket, place them in the forward location, and bolt them back on using grade 8 hardware.

Here is an article covering the swap in detail, with lots of great pics:
http://coloradok5.com/52inchspringswap.shtml

You can even get fancy and buy Kurt's new mounts that give you additional mounting options.
http://diy4x.com/cart/index.php?rout...product_id=120

For the rear you can use stock 52" springs again, or go with a longer option, such as 3/4 ton 56" long springs. Other popular options include 57" F-150 springs which stretch the wheel base a little, or 88-98 63" long rear springs from a 1500 2wd chevy. The first two longer options allow you to retain the stock spring hanger in the rear and move only the shackle mount location. This is fine, b/c the shackle mount is coming off anyway. Here is the only money you have to spend (and there are other ways to do this mod for free, but this is the cleanest, simplest, and best method) on your lift. The shackles need to be flipped down. This gives you better suspension travel and ride quality, along with enough lift to match the front. Here is an example of an aftermarket shackle flip hanger:
http://diy4x.com/cart/index.php?rout...product_id=125
http://diy4x.com/cart/index.php?rout...product_id=112

I like Kurt's design for the incorporation of traditional simple shackle plates instead of the GM style stamped ones. This allows you to fine tune the shackle angle by adjusting the length between the holes. This is an important step b/c a good shackle angle is important. It should be between 30*-45* from the vertical axis, like this when looking from the side \ . Having a proper shackle angle gives you the most travel through the suspension travel of the leaf springs under droop and compression. A vertical or straight up and down shackle gives a harsh ride and very little down travel or droop. A shackle angle greater than 45* limits up travel or compression and provides a mushy ride quality and can be unsafe. If running the 63" springs both the shackle mount and spring hanger must be moved.

I mean that's about it for suspension, you can add F-250 shock towers to the front to allow for use of a longer shock and there are alternative mounting configurations for the rear, but all that is just details.

Next is steering,
CROSSOVER one word one solution. No rig should see offroad use without it. Its simple to do and only has a few variations depending on your front axle choice.
All you need is a 2wd steering box and pitman arm. A Jeep cherokee (XJ) steering shaft is a good upgrade to do while your at it, and they are plentiful and cheap in wreaking yards. If you desire to stay 1/2 ton then the dana 44 front is the way to go, I recommend the 3/4 ton version as they are 8 lug and allow you to run a matching 14bolt full-floating rear axle. The best option is to run a dana 60 front axle but they can be hard to find and expensive (~$800-$1000) when compared to a dana 44. One thing about the d44 is that you will need to find one that has a passenger side "flat top" knuckle that can can be machined, drilled and tapped, for the steering arm studs. Flat top knuckles are available aftermarket through a wide variety of vendors.
Here is just an example, there are others that maybe much cheaper
http://www.polyperformance.com/shop/...es-p-2407.html

You will need the crossover drag link and possibly upgraded tie rod.
here is a link to an example of a good crossover kit:
http://offroaddesign.com/catalog/Dana44crossover.htm
http://offroaddesign.com/catalog/Dana60crossover.htm

Another good upgrade for running tires larger than 39" is Hydraulic Ram-assisted steering:
http://offroaddesign.com/catalog/PSC...%20I%20Need...

A rig outfitted like this can clear up to 42" tires without major trimming. It will be significant, but not too major.

Now it comes down to a matter of tire choice and this should match the intended use of the truck. This basic setup works well for hardcore rockcrawlers to street queens who want the offroad look and a better ride.

Here is a pic of my old Blazer on 39's


I had the full monty... Rear springs up front, F-150 rear springs, traction bar, Dana 60 front, cross over, ram assist, 14 bolt FF rear w/ 3/4 ton disk brake swap. It was a great truck and rode and drove great on and off road.

[79 jimmy]

wow man, thanks for the help. although i already did all the spring ****, the info is nice. lol. i will probably do that crossover steering set up. this is an embarasing question but idk what axels my jimmy has...
how do i find out? lol.

i probably wont go much bigger than 35-39, somewhere in there. 35" will be my next size choice, but then i may go bigger. so the hydro steering is an option i may go with, i already knew about those systems from other articles and tv shows. lol thank you tons tho. and i would appriciate any further info u gots!

[str8axle55]

It should have 12 bolt rear, and 10 bolt, or Dana 44 front. You will be pushing the limits of the stock axles if you plan to run the 35`s off road. What gears do you have in it now?

[Zoomad75]

I'll add a some here. You've got a good start. Thank goodness you yanked the front blocks and have learned some things along the way. NCgamedog gave some great advice to go big. I've got a much milder build than his. How far you want to go is going to be the biggest factor as to what you want to do. If you want to go full on rock crawling, 37" tires or bigger, you'll need to get the size and flex that NC was talking about.

I'm not going rock crawling with mine and use it for the primary purpose to go ride in the mountains on trails summer or winter. I've got 4" of lift to give room for 35's done with 4" springs up front and a shackle flip out back. It rides nice and flexes enough for my needs. I'm still running the stock D44 up front and the 12bolt out back, however, they are open diffs which limits some things. First it limits breakage on weak axleshafts, provided I keep my heavy right foot in check. It also limits where I can go, so I have to make sure not go where I've got no chance of driving out. I've broken that rule and came out with a barber pole'd driveshaft as the result. I got lucky that's all I broke.

I do plan on at least locking up my rear axle, but I won't do that until I swap in a 14bolt full floater. It won't be for rock crawling, but for the strength and peace of mind I won't have a wheel rolling out from under when a shaft breaks. Ultimately, you need to build it to meet your needs on where you want to go with it. Everybody is a little different and the builds match those differences.

[79 jimmy]

i dont think i wanna build it for crawling as such, but more as a durable, multi-purpose wheeler. i love trails in the woods, and the ocational muddy run, but thats really all i've gone and done. i'll probably do the 3/4 tone axle swap even if i dont go rock crawl it, cause its better to be safe and strong, than walking home. 35's-37's are the tire size i wanna do. i already know that. thanks for every ones' input here, i am new to this and i really wanna do it right and know my ****. lol. how do i identify what axle i have, where are the stamps of lables? and is there a way to figure out what gears i have with out pulling the cover off and actually looking? i dont got a problem with doing that but is there an easier way?

[ncgamedog]

To identify GM 1/2 ton rear axles, simply count the bolts holding the diff cover on. 10 bolts = 10 bolt, 12 bolts = 12 bolt

For the front, 79' could be 10b or D44 (most likely 10b). A 10 bolt front will have a more circular shape to the third member housing (hog's head/pumpkin). The Dana 44 has a more octagonal shape. Both have 10 bolts holding the diff cover on, so this is not the best identifier. A dana 44 should have "44" cast into it somewhere, but I have seen some that dont. You may have to scrape the grease/crud off to find it, if there is any.

10 Bolt Front



Dana 44 Front

[ncgamedog]

To those comments about the setup I portrayed being a "rockcrawling" setup...

While it is true that the suspension I mentioned works well for rockcrawling, This setup lends itself very well to mild rigs as well. It is my belief, and has been my experience, that using stock springs to "lift" ( I like "improve" better) suspensions on just about any 4wd application provides a better end result. There are cases where custom springs can be made to suit the exact particular application, but is usually cost prohibitive for most folks. There are also a few (very few) mass production suspension companies whose products actually offer suspension improvements over stock. For GM full size trucks, the only company I have had any luck with is Tuff Country. Their 3" and 4" FRONT leaves in the EZ-Ride line provide an improved suspension travel, ride quality, and yes, lift. MOST of the companies offer suspension lifts with looks as the primary goal. Unless heavy towing (>8000 lbs) is a vehicle requirement I stand strongly AGAINST rear lift leaves. The shackle flip configuration is a major improvement in suspension design on GM full size rigs. It offers much greater tune-ability, ride comfort, and travel.

Another note about front lift leaves from ANY company is that the shackle angle is not taken into consideration. Any mass produced lift leaf (greater than 3") causes the shackle angle to be vertical, at minimum, and usually forward. If running an aftermarket leaf the shackle mount needs to be moved forward on the frame to achieve a proper angle. I can offer instructions on how to do this very simple modification to anyone interested.

Yes my truck looks "big" in the pics due to the 1-tons and 40's, but It sits very low considering. I actually only netted 4" lift total, and 1" of that lift is due to the increased tube diameter and perch height of the 1-ton axles. This type of suspension setup usually only provides 3"-4" of lift. Some folks have modified this formula to go bigger by running rear lift springs in the front and shackle flip hangers with lift built into them. I stick to the least amount of lift possible that provides sufficient clearance.

I believe that this is the best setup for ANY functional offroad use, the fact that it is low buck, is only a coincidence and bonus.

You could run this exact setup with 1/2 tons and 33's and it would "look" great! Plus, none to very little fender trimming will be necessary.

The ONLY knock against this setup for a daily driven rig that I might admit is there MAY be an increase in body roll due to the soft nature of the stock rear springs in the front. For me it was never an issue, but this can be combated easily by adding an additional leaf to the front pack. DO NOT READ "add-a-leaf" kit. Typically, a 2nd leaf from another stock rear pack cut down to fit as a 3rd leaf works well. There were also two versions of stock rears, 4 leaf + overload and 5 leaf + over load. The 5 leaf pack works very well in a front application and provides much less body roll, albeit, more lift. I opted for the 4 leaf pack and added two thinner leaves from a 1/4 ton truck, I believe 79-83 Toyota rears. I cut them to fit in the GM pack as 3rd and 5th leaves, netting a 6 leaf pack. I would recommend starting with a stock pack and tuning to suit your own personal needs and comfort.

Good luck with your build, and I'm sure you'll enjoy it no matter how you set it up. Looks like a great start

[79 jimmy]

so went out and looked at my axles. rear, 12bolt. front, 10bolt.

idk the gearing... but i'll figure it out soon.

[McMurray76]

Good reading here. I'm in.

[rome704]

Yeah there is a alot of info given

[mud slut 350]

Mines at 4 inchis right now but im planning on doing the 52 swap on the front of mine like ncgamedog did but in adition using 4" rear lift springs for 8" there and using Sky-manufacturings front spring perch drop to give me a total of 12" on the front then with the rear doing the shackle flip and eight inch springs for the 12" shes gonna be mostly mud and some trails.

[79 jimmy]

so i've been gone a while.. been broke, and wheelin so havnt done a whole lot.. had been laid off, had college debt.. not alot has happend.. but some updates if i can find the pics.. lol.

this is how it was..


and i made a few upgrades.. mainly dress up and a massive tune up, but i deleted the emissions, meaning i had to get a different carb.. and i was low on cash flow so i got a different quadrajet.. mine is a 79 and i put a rebuilt 69 off my buddies hot rod c10 on it, along with his intake.. i also (recently) learned that my truck has a 2 bolt main.. so ill be buying his rebuilt, cammed, 350 4bolt main.. when i blow mine.. but other than a small chevy oil leak.. shes healthy.. but i freed up alot of ponys but this tune up and gained a couple mpg.. this is what it is now.. except ive cleaned up some wiring and made it more tidy.


then i found these for 40 bucks at good will...

their awesome, bolt to tailgate and have shocks to keep em open and alot of space.. only drawback is it makes the gate a little heavier to lift.. bummer. lol

didnt go wheelin for a while but i did do little things with my 4 year old nephew around town.. like going to the river bank.


sadly had the truck over a year before i ever took the top off.. this was the day i put my front shaft back in (been out since lift...) and decided to go find snow.. early march of 12..


sent this pic to my buddy with a yota and he said, "lets go to the coast!" i was only like 30-40 miles away at my girlfreinds house so when he drove thru that town on his way, i loaded up and went with him.. after doing this for the first time.


its way better topless in public. lol

hadnt ever wheeled in sand...
didnt do bad for not airing down at all.. wheeled all day following my experienced yota freind.. then on my way back (alone) i got cocky...


yeah... next time i aired down.
to 12 psi... ended up following samuri..
this was like the only time i stopped for a pic, yes.. poser pic...


oh yeah, guess what, it rains in oregon... so instead of putting top back on, for one day of rain in the summer.. i did this for like 30 bucks..
tarp
elastic straps
and a eyelet kit.

yeah camo

this was his yota back then..

since then he bobbed it, put rock sliders on.. and a few other helping touches.

randon pic from first trip before i got stuck.


followin samuri is dangerous.. lol.. they are alot smaller and i had fail in judgment.. tight brush.. didnt notice this till some time later.. didnt know it even happend when it did.. kept going.. stopped like 45 minutes later for a drink.. got out... "son of a *****!" lol


then we kept going.. and found out why it was drift wood shore.. lol.. and i found out my tires like to toss logs and get stuck on em..


oh and the taillight happend in the woods..

but back to getting stuck on driftwood..

gas tank took a nice blow.. just a dent tho.

and a body seam that came unwelded... flex to hard on the trail i guess... once again, following a samurai's line on a quad trail, adn i didnt notice this till i washed it the next day but i do remeber a big SNAP sound..


drilled out the welds, and re welded it..

then i lost my job, she got parked..

just now getting her back to wheelin and i have to replace the steering knuckle u joints tomorrow. hopefully a weekend trip in october.. we'll see.

heres more random pics..



deleted sway bar a few weeks ago.

[b454rat]

Sweet build. I've been out of work since April, just got a job starting Monday for half of what I was making. But hope I can get another truck to build up, miss wheeling and really need a "beater" so I'm not destroying my late fathers 08 Tundra.

I wouldn't worry about getting a 4 bolt motor. If you planned on boost, nitrous or something like that would be OK, but for what your going it's just money wasted on someone thinking that 4 bolts are gold. Whatever you build make sure it's balanced and will be fine.

I had a .030 over 454 built for my Malibu. Not a drag racer, but nice street engine. 2 bolt main, cast crank, small rods, KB heuper-whatever there called pistons. Motor is about 350-375 horse, runs awesome. No need for 4 bolts. Last motor I built was a more serious 468, only thing different than my current engine was GM alum. heads and a bigger cam. I had that to 7k one day, and no issues.

I'd look for a 400 block. They are great engines and make a ton of torque. Also all the parts will swap from your motor....

[79 jimmy]

thats badass, im glad you found work. im doing temp work for a company but their hiring me on soon so hopefully it lasts. anyways, you dont think that a 2 bolt main might give me problems at high revs while wheeling? isnt it kinda a weak bottom end?

[b454rat]

I had the same question 10+years ago when I had my first 454. Was told by a couple very good engine builders, as long as you aren't maintaining high RPMs for long, for example in a boat, then 4 bolt main is just something to brag about. The first motor was bored to a 468, Comp Cams Extreme Energy 284 I think, GM alum. heads, 10:1 comp. fully balanced, made about 550 horse. Had a manual v/b TH400, 9" rear with 4.10s. I shifted it a couple times at 7k. Quick stabs at that RPM is OK, but if your trying out for NASCAR, then you will need 4 bolt along with some other stuff.

The motor in my current car is very similar to the one I just typed, but has iron heads and a smaller cam. Tach is way off, but missed 2nd gear shift and the tach bottomed out, guessing at least 6 or 7k. Motor is just fine. I wouldn't worry at all running a 2 bolt in a truck. Mud racing or pulling is different, but with what you described your wheeling, it will be fine. Spend the money elsewhere....

[79 jimmy]

Originally Posted by b454rat

I had the same question 10+years ago when I had my first 454. Was told by a couple very good engine builders, as long as you aren't maintaining high RPMs for long, for example in a boat, then 4 bolt main is just something to brag about. The first motor was bored to a 468, Comp Cams Extreme Energy 284 I think, GM alum. heads, 10:1 comp. fully balanced, made about 550 horse. Had a manual v/b TH400, 9" rear with 4.10s. I shifted it a couple times at 7k. Quick stabs at that RPM is OK, but if your trying out for NASCAR, then you will need 4 bolt along with some other stuff.

The motor in my current car is very similar to the one I just typed, but has iron heads and a smaller cam. Tach is way off, but missed 2nd gear shift and the tach bottomed out, guessing at least 6 or 7k. Motor is just fine. I wouldn't worry at all running a 2 bolt in a truck. Mud racing or pulling is different, but with what you described your wheeling, it will be fine. Spend the money elsewhere....

sweet. but i am probably still gunna build a 4 bolt because thats the motor my buddy has for me to buy, and we know the history and have a brand new cam and some other **** just laying aroung for it.. and he wants to sell it to me cheap. so eh, why not? lol

[b454rat]

If the price is right why not....