SMason's 78 GMC K25 4x4 Build Thread

[Scott M]

Howdy Everyone!

Want to start a thread on my truck like everyone else...I have been working on this truck since Feb 2014  It has been a slow process for me and this is my first truck of its kind. heres a little about the truck

Bought it off of craigslist for 1600 back in August 2013 It was all stock had surface rust on the frame, had holes all in the fenders hood and bed, it ran good drove descent and pretty much everything worked for the most part the inspection went out in sept of 13 and took it in and it passed.  I drove it around for awhile took it to the beach often and then I got my income tax check beginning of the year 2014 and decided to put a 6 inch suspension lift on it.

here are some pics before the lift during and after.....

[Scott M]

Then on the maiden voyage of the lifted truck to the beach I ended up locking up the motor..the motor had to have blown a seal because there was oil all over the tranny and transfer and it burned up.  I had it towed home.

I just so happened to have a ZZ4 crate motor sitting on an engine stand that I had bought to throw in a 98 jeep TJ I had but ended up trading the jeep so I had the motor sitting.  The ZZ4 the previous owner had it in a YJ rock crawler and was running a TBI on it.  I decided that instead of keeping the TBI i would convert it back to Carb to throw in the truck.  I bought a new GM performance intake that originally came with it and bought a Holley 670CFM Street Advenger Carb to go on it from jegs....

I then began the process of pulling the old motor and here are some pics...

[Scott M]

After I started looking more into the ZZ4 and taking the intake off I flipped it over to check the main bearing tolerances and found one bearing was scored or whatever you want to call it pretty good so then I made the decision to take it to the machine shop/performance engine guy in town and he fixed it up pretty darn good for the price I paid.  He tested block and did the work he needed to do to clean it up, new cam bearings, main bearings, turned the crank, felpro rebuild kit, tested heads they were warped so he decked the heads and did a valve job on it for free, new piston rings and high volume oil pump. and i think thats about it and put it completely back together cost me $998 out the door

here are some pics after the rebuild...

[Scott M]

Then it was time to start putting the motor in bought new motor mounts and ended up taking the bed off and bedlinning the frame after I killed the rust with OSPHO and sanded it down best I could...  I also realized that all my body bushings were shot so I bought a new set of bushings and decided that while I was replacing those that I would go ahead and put a 2 inch body lift on it...

then i determined that the inner fenders and front fenders were too far gone so I bought new aftermarket ones and found a used bed in better shape than mine on craigslist and went and picked it up in Houston, tx.

bought new holley HV mech fuel pump, hooker headers, SS braided Tranny Cooler lines all kinds of stuff, pretty much alot of new stuff lol

here are some pics from all this..,..

[Scott M]

All this has been over the past year motor blew up end feb 2014 motor rebuilt summer 14 and been trying to get it all together since then

I ordered a clamp on exhaust kit to get me by...turns out i dont like it so ima take it to the muffler shop get them to weld it up for me, new batter tray box, had to switch the gas tank from the passenger side to the driver after i realized the bed I bought it was on the other side

Recently drug it over to victoria bout a 72 mile trip pulled it with my ford had been doing final touches to it and breaking in the motor still i guess you could say prolly put about 20 miles on it running. I have installed after market guages for coolant temp volt and oil pressure, aftermarket Tach,

Putting a radio and small sound system in it now, I got a JVC radio, a 10inch pioneer shallow mount sub and box, pioneer 900 watt amp and 4 guage amp wiring kit,

Bought a new rear driveshaft from Tom Woods and upgraded the output yoke from the 1310 series to the 1350 series happy with all that

NOW here are the problems

I am still currently figuring out the windshield wiper switch problem I am having, the front driveshaft I just dont think is going to work and the emergency brake rear cable is cut (my stupid mistake)

with it lifted I am going to have to figure out how to rig them up so they work for inspection still dont know what to do....

[illinoisk30]

Welcome from Northern Illinois. Nice truck and great work on the mods. Are those Ground Hawgs or Grand Prix's on your truck? When I was younger my buddy had some Grand Prix brand tires, I believe 40's on his Blazer. They were the cheaper alternative to Ground Hawgs. It is also nice to see the all spring lift instead of blocks in the rear. Keep up the good work.

[Engineer]

  I approve.

[FlatBlack77]

nice build!

[Irish_Alley]

nice

[Scott M]

Well made small progress on the truck yesterday...here in mid-south tx we have been getting hammered with rain for the past several weeks 50-70% all week and last too so havnt been able to do a whole lot till yesterday and it still rained about 3pm lol

I got the rear bumper holes drilled and the rear bumper mounted again had to raise it up and drill new holes because of the 2" body lift it turned out ok this is as high as it will mount with my current set up.


then I got my new pioneer sub in from ebay this past monday and the new box from walmart.com  the box is 5" wide top to bottom it pushes on the seat a little bit at the top but since I have it in the passanger side its not that bad.... did have to make the hole bigger for the pioneer shallow sub about a 1/4" all the way around.




weather depending this weekend will determine if I will be able to mess with the emergency brakes some more....

[Scott M]

Was able to completely finish wiring up the radio...did not use the stock harness ran all new wires to the ground block, ignition fused and hot fuse in the fuse block along with new speaker wires...

I installed two new 6x9 speakers behind the seat and hooked up the sub, man it sounds really good! Perfect for the truck im glad i went with a 10" sub its all i will need!

I also messed with the praking brakes and i am able to put the truck in drive and get it to hold....reverse thats a different story it creeps still but them cables are so dang tight that idk if it has anymore to give....

I think its time to redo the drum brakes and replace the emergency brake cables instead of having them rigged like i do....plan is to take it try and see if i can get them to pass it on inspection and then hopefully replace the brakes in the drum in the few months got my fingers crossed being in texas and on the coast we have no elevation changes here and the larking brake is used very rarely!

[Scott M]

I took the truck in this morning to get an inspection to an old school service station and it passed the state safety inspection!! Heck ya! im pumped now just have to get it registered with the new texas two step program! one step down!

Left to do too get it fully capable on and off road is to fix my front driveshaft problem

I plan on changing the oil again even though I only have about 50 miles on it since the rebuild.

I have read all about the ZZ4 break in and stuff and I should be pretty good to go I believe supposidly with the roller cam the motor breaks in within the first 20 min or so along with all the other things like the rings and main bearings I did the graduale pulls rolling from like 10mph up to 45 or 50 with half and then 3/4 throttle so hopefully this is all I have to do... I plan on not getting crazy for the first 500-1000 miles but the amount of miles I actually drive the thing this might take forever lol Im going to drive it to work everyday for the nxt couple of weeks to help build up miles (5 mile drive in city traffic) should keep from driving at a constant rpm and stuff and drive it around town hopefully i can get to about 500 miles in the next 2 weeks, I might make an extended trip to the other side of town after work in order to gain more miles that would put me at about a 25 mile trip per day....Ima have to make more loops then that to get to 500 in two weeks lol Ill just have to do the drive twice instead of 1 time no big deal hopefully lol

[Scott M]

anybody know where you can buy one of these or what it is actually called? the throttle cable screws into it at the transfer case and i believe there might be different ratios you can buy to account for tire size? Anybody ever messed with it? or replaced and found original or aftermarket setup?? Mine is super loose? has alot of play in it...

[BBM3]

That is a speedometer ratio adapter.
It should be tight to the T-Case.

Is your speedo working?
If so is it indicating the correct speed?

If yes to both just snug up the adapter and you are good to go.


Nice truck.
Nicer white Lab. Looks just like our white Lab Charlie.

[Scott M]

BBM3

I replaced the speedo cable and it worked for a bit, then it just stopped, I got around to looking at it and the cable was all twisted up at that very end, so they are cheap enough I was going to replace it again, ill try tightning down on that piece today to see if it helps to not mess up the new cable...

ahh yea hes a smart dog and good one too! I have a funny video of him climbing a palm tree to get a squirrel pretty funny! squirrel 1 dog 0 lol