73 K10 Build

[78gmc1]

Well i guess i can start a build thread on this 73 K10 its going to be a slow build anyways i picked it up last month in Bullhead City AZ because i really wanted a squarebody 4x4 It has a 350 with a th350 the body has some rust and a lot of bondo that i didnt notice till after i bought it and also the frame was cracked pretty bad by the steering box

here are some crappy cell phone pics

[jrdv]

I think 73 4x4's are pretty rare. Seems like there was a strike that year or something?

I always liked the early square bodies. We had a 78 3/4 t 4x4 when I was a kid.

Have fun with the build.

John

[rgunlock]

Congrats on the new truck! What are your plans for it?

[78gmc1]

Thank you yea i have a 78 2wd gmc c10 too

And my plans on swiching out the auto for a nv4500 if i can find a decent one im planning on pulling the engine today and finding a better one

[rgunlock]

I hear you on that. I've got a NV4500 I pulled from a donor and had rebuilt for my 59 project. I've been seriously thinking about dropping it into the 78 since I'm a lot further along with that project and it would be easier to do without a body on the chassis.

[78gmc1]

yea i would probably do the same and try to find another one for the long term project

well i pulled the front clip but didn't pull the motor as i planned that will have to wait till Monday afternoon but its just about ready too

heres some pics of the clip, engine, and frame that needs to be fixed

[Daubs]

That looks like an 8.1L???

[78gmc1]

Yup your right its a 02 8.1

[Daubs]

You are going to love that motor! Mine has gobs of power (in a seven thousand pound CC). Your K-10 is going to fly!

[78gmc1]

yea i forgot how much tq and hp dirty larry said he is making but im sure ill be happy with it

[Daubs]

Mine is factory rated at 340 HP and 455 lb·ft torque. With the Volant and program, I'm guessing somewhere in the 375 HP range and close to 500 lb·ft(?).

Know that your 8.1L is probably going to have the "piston slap" or "cold start knock" issue. Mine started around 30k. Buddy who runs service at GM dealer said some 8.1's are famous for eating a quart of oil every 3k miles. Mine piston slaps in morning, but doesn't eat any oil what so ever. It's a strong engine for sure.

[78gmc1]

yea ive read that some like coolant too so we'll see if it does either i cant wait to get it in there but have to order some more parts and save a little more $

[DirtyLarry]

I got my harness from Howell Engine Development and they did the ECM tuning as well. They Removed Torque Management, Removed EGR, Removed APP (electronic throttle) then added a 91 octane performance tune. They claim this tune was dyno’d at 425 HP/ 550 lb. ft. of torque on a bone stock engine. I’ve never had it dyno’d myself but the L18 in the K10 will run circles around the stock L18 in my 2001 HD truck. They run like two entirely different engines. The tuning really makes a big difference.

L18’s do like oil. GM had a few different bulletins out there to address oil consumption but none of them really worked to cure the oil consumption issue 100%. In my opinion the oil consumption problem with the L18 is related to the fact the engine does not use a positive crankcase ventilation valve (PCV). The PCV is built into the intake manifold, and that built in design doesn’t work well IMHO. Some engines do drink coolant too. The L18 in my stock 2001 HD truck drinks a quart of oil every 1,200 to 1,500 miles like clockwork and has since the day I brought it home from the dealers lot in 2001 but does not use any coolant. The ’78 K10 with a 2002 L18 doesn’t use oil but it likes to use coolant. Not much, but it needs a top off before every trip. Still great engines. I would take an L18 over any diesel any day of the week.

[78gmc1]

Thats alot of torque for a bone stock engine ,Thanks Larry ill look into the Howell harness and their tuning

[Daubs]

Google search for 8.1L performance parts and you will find Raylar. They have aluminum heads, intake manifolds,etc., the Big Block. Pretty impressive numbers for non-supercharged engines. Toss on the SC and WOW!

[78gmc1]

Originally Posted by Daubs

Google search for 8.1L performance parts and you will find Raylar. They have aluminum heads, intake manifolds,etc., the Big Block. Pretty impressive numbers for non-supercharged engines. Toss on the SC and WOW!

That would be nice but man are they are they Expensive

[Chevymaniac]

What did you pay for the 8.1L?

I thought about doing this but also thought about a BBC stroker.
Not sure which route I will take.

What are you going to use for tranny?

[6BT 56]

Im a Mercury marine tech and have seen hundreds of 8.1's. Everyone of them used oil . Nothing crazy excessive, but they did. We had a few rebuilt , bored .30 with deck plates and a real good hone. The oil consumption was cut by abt 90% on the rebuilt vs a new one. In my mind they were just sloppy engines. That said I only saw 1 come unglued in the last 10 or so years. Also most of the boat engines are run at 3500 to 5000 for endless hrs. I got to say I think this will be a killer truck eng. Looking forward to your build .

[Daubs]

Originally Posted by 6BT 56

Im a Mercury marine tech and have seen hundreds of 8.1's. Everyone of them used oil . Nothing crazy excessive, but they did. We had a few rebuilt , bored .30 with deck plates and a real good hone. The oil consumption was cut by abt 90% on the rebuilt vs a new one. In my mind they were just sloppy engines. That said I only saw 1 come unglued in the last 10 or so years. Also most of the boat engines are run at 3500 to 5000 for endless hrs. I got to say I think this will be a killer truck eng. Looking forward to your build .

Appreciate your history and insight with the 8.1L. Mine rarely sees 3000 RPM, so I'm thinking it will probably last me quite a while. And is one of the rare few that does NOT burn oil.

[jon75]

GM's 8.1L engine was always thought to be an improved version of the 454. But when I was working in Grand Rapids, MI for Chevrolet, one of GM's engineers came to our dealer and talked about one of the Avalanche 2500's we had that was going through oil and the customer hated it. He told us that these engines were not developed for street use, but they were engineered to run in service applications; ie: tow trucks, generators, marine applications, etc. So the fact that they were designed for non-street use, they weren't designed for street-type service intervals. But the up side of that is you will have a workhorse that won't quit for anything. Good buy my friend.

[6BT 56]

What oil pan were you plannig to use.? I have a 425 8.1 mag hidd out back. It thru a rod but did it in the best posible way . Didnt wreck anything beleive it or not. A piston , rod assy and a pan and it could be good to go . it's in the back of my head for some day. no one else knows its there .

[78gmc1]

ill Be using a NV4500 transmission. i think i can use the stock oil pan but i am going to be using the ORD High clearance crossmember. Also thank you all for the good info and checking out my build Haven't really had time to work on it because my 78's clutch disintegrated but got that fixed today