Restoring my dad's '86 Custom Deluxe

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HotRodPC

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85 K20 LWB
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I'd be happy with 5-7. Lol
I'd tickled as a pig in **** to get to 10. Realistically, I have a feeling it's going to me more like 8-9.

People forget, when you lift them, you've got more wind drag, and lift usually means you're turning bigger than OEM tires. All of which drops the mpg.
 

richiemoe

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You're smoking crack if you think you're going to cruise 80-85 in one of these trucks. You compare that YJ in weight, height, tire size to one of our trucks, and are you going to lift it? Tire size, V8 that will be screaming at high rpm with a reliable NON OD tranmission, or a weak 700r4 that you'd kill probably in the first long trip. And 10-15 mpg is a pipe dream.

If you're build a K20 to do all this carry a load of top soil, pull a 5th wheel, have some wheels, lift and tires to go raise hell, you need to a have serious reality gut check. And I'm exactly where you are buddy. I'm converting a K10 to K20 myself. I've converted the 10 bolt rear that had 52in springs, to 56in 3/4 ton C6P spring pack and a 14 bolt full float with 4.10 with Detroit Locker. Just changing the front 10 bolt to 4in Rancho lift springs and a 10 bolt 6 lug that is set up with 4.10's and an ARB Air Locker that I'll change the brake backing plate, hub and rotor to 8 lug. I too would like 35in tires, but don't care for the 12.5 wide, the expense and the probably tire damage if I get aggressive wheeling so I'm most likely going to go with 33in tires or actually since now going to 16in OEM stock wheels to a 305/75R16 that is supposed to be 34in tall. Since I'm not financially able to build my small block I wanted for it, I going to take the 454 outta my C20, and have now acquired a Th400/NP208 combo. Why a Th400? Because I've realized even with a 700r4 and having OD, it's not going to give me all that much of an mpg gain if any at all to give up all that reliability. And this type vehicle is not being made for a gas sipping daily driver street princess. It's going to be a work horse for when needed, recreational use, and hell raising from time to time when I get it out to the trails at the lake or the river. And I don't trailer my ****. I drive my **** just like I did back in the street racing days and back then it was my daily driver in stop and go Los Angeles traffic. Sooo, that being said, I HOPE to get 10mpg, and that's hoping hard to get 10mpg to and from my places of recreation, wheeling whether it be in the mud, river bottoms, or canyon trails, camping. picking up a load of cow ****, hauling a few sheets or drywall etc. And I'll have faith it'll hold up with maybe the occasional front axle break whether it be a stub shaft, axle or whatever, but the rear 14b FF will get me home and so will that Th400. Soo, as lead footed as I am, an 80mph cruise guy myself, this truck realistically, I'm looking at 65-70 and I'll just have to drive the slow lane and get passed a few times with the engine screaming a little bit to get where I'm going, and I will be driving it to my dad's property 75 miles away frequently. It's not going to be a daily driver. So when I can afford the fuel to have the fun or do the work, it'll be ready to do it. And the occasional bad weather snow day or 2 a year we might get.

Just remember, you can't hang with the big dogs if you piss like a puppy. You gonna play or are you going to sit on the porch and be a spectator? Just keeping it real !!! :shrug:

So if you want more than that out of it, better mpg, more power, more reliabilty, then consider an LS Swap with a 4L80-E to modernize it a bit, but still keep in mind, these trucks are heavy bricks and not aerodynamic at all, but with the right combo, you'll have all the power you can use and might get 14-15 mpg with the correct gear ratio, tires size set up and the correct tune in the LS package.
Thank you for keeping it real!!!

The reason i choose over 500hp, was to ofset any loss of power, so i could maybe go with different gearing and larger tires. When I'm towing, i won't be using the 35's. My dad has a set of winter tires on a set of rims, and a set of chrome rims and tires for the summer. Nothing super special or crazy big, but they look nice. I'd put in the 35's on for the dunes. Which will have 5-6 psi and I'll be in 4x4 low the whole time. Plus, the sound of a 500hp engine sounds amazing! Ha And so i can say it is a 500hp engine...

This will be a long term project. Since i already have a cherry picker and engine stand. I think i can build the whole engine and mount it to a transmission out of the truck, then add the transfer case when it is in. So i might just stick with the current setup for now.

I guess in my head, everything seemed "simple". With the current 4.3l the truck easily pulled a camper and a trailer with three quads and two canoes on long 5-24jr drives. Like to the UP or out west hunting. So i thought by upgrading what is in it now with stronger versions, all would be peachy... haha

Maybe i will pull a 350 or 400 trans from another truck and see how i like it. I am worried about an LS swap, so maybe ill pull out a big block and see how that goes as well. My buddy's dad has two square body's sitting in his yard. One has a big block and another a small block. Both run! I might buy both for parts (if they are cheap). Not sure yet.... They are long boxes, mine is short.
 
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MikeB

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I've certainly read some outrageous mpg claims on truck forums. But here's something that will blow your mind: My 82 C10 with 250 six, 3-speed manual trans, and standard 2.73 axle was EPA rated at 19 city / 26 highway (on level roads).

The highway speed limit back in the 80s was 55 mph. At that speed (and low RPM) I suspect you'd have to bury the throttle to maintain 55 up the slightest hill, or even downshift to 2nd gear. So real world mileage was probably less than 20 highway.

No way 2.73 should have been standard with that lame six. Should have been a 3.23 or 3.42, but then the EPA ratings wouldn't have been as high. Must have been a terrible surprise for guys who bought a new truck off the lot not knowing anything about axle ratios.
 

MikeB

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And so i can say it is a 500hp engine...
Not a good reason. Kind of like wearing shoes that hurt your feet because they look cool.

I suggest you focus on maximizing torque in the RPM range where the engine will spend most of its time. Torque is what spins tires and throws you back in the seat. It's what make cars & trucks fun to drive on the street.

Then again, if you plan to make regular runs up to 5000-6000 RPM, then by all means, forget torque at 2000-4000.
 

richiemoe

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True... ha

On the dunes, im usually going up steep hills in 2nd and thanking God for a rev limiter, in the jeep. The dunes wont be a regular thing with the truck. Neither will towing. I just want the option. I'll mainly just drive it hard around city and highways. Vehicles are made to drive, not just look at. Although, a car show here and there would be nice.

Would converting to a manual trans be the best route for what i want?
 

Honky Kong jr

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True... ha

On the dunes, im usually going up steep hills in 2nd and thanking God for a rev limiter, in the jeep. The dunes wont be a regular thing with the truck. Neither will towing. I just want the option. I'll mainly just drive it hard around city and highways. Vehicles are made to drive, not just look at. Although, a car show here and there would be nice.

Would converting to a manual trans be the best route for what i want?
I think for play the manual trans set up sucks.....now this is my opinion.....speed shifting a sm465 is a joke now a divorced transfer case and a super T10 or a Muncy or even a T5 would be fun, but that's the only way I'd go manual in a play time truck.
 

richiemoe

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Ah, so much for nicer to respond on a computer now, instead of my phone! ha

I like a manual for off-roading, much more control. But i've never really messed around with one for playing around on the streets. I've also never driven an automatic that had a performance torque converter in it, don't they only take off at a specific RPM?

At the dunes, i'll be in 4x4 low, i'm not sure when i'll need 4x4 high really, since i won't be mudding, and i'll mainly just be driving around and having fun in 2wd most of the time. For the few times that i'll be pulling stuff, i'm not really going to be worried about high performance. I'll probably just keep it in D if i'm hauling anything, and let it go into OD if i'm hauling and it is flat. For a few years, i'll probably keep the truck as is, with the 4.3. Maybe upgrade the axles, maybe. The v8 engine will be built first, on my engine stand.

I hope to get some pictures posted soon!!! Some older ones, current ones, then the progress ones. I have until it gets cold out to work on the truck, then all focus will be put on the jeep, until the frame and body are finished...
 
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richiemoe

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