GMC / Chevy Getting a 1969 Chevy K20 back on the road

Greg

Make RME Rockcrawling Again!
Admin
The parts truck (1979 K30 longbed dually) has been hauled home, I'll have to swap axle hubs F & R, want to put discs on the back too. Need to start pulling the axles ASAP. The parts truck should have a NP205 with a 32 spline output shaft and the round 6 bolt pattern.... I *think* the 4L80E and 205 will bolt up, but I need to verify that.

Anyone want a cheap K30 cab and frame??

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Greg

Make RME Rockcrawling Again!
Admin
Got the 1 Tons out of the donor truck, along with the SM420 & NP205. Decided to pull the diff cover and check the gear ratio, they're 4.10's which is fine by me. I plan to run an overdrive transmission and bigger tires, so it should be just fine. I don't plan on needing a rear locker for the time being, so it'll stay opened.

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I decided to clean up the axles by spraying Muriatic acid on them, next step will be to degrease and pressure wash them further.... then tear down the hubs F & R to get them ready for SRW duty. At some point I'll paint them up and make them look good before install.

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mbryson

.......a few dollars more
Supporting Member
Pretty wild that the rear axle tires can almost fit inside the width of the front, in that configuration


I found that very interesting as we shifted from 3 wheelers to 4 wheelers in the 80s. The first 4 wheelers sucked to turn. About 85 or 86 Suzuki came out with the quadsport and Quadracer (I think that's the names?). The front track width was significantly wider than the rear and they could actually turn.

I assume GM learnt that in the 60s or something? (Maybe before?)
 

Greg

Make RME Rockcrawling Again!
Admin
67" unless it's the C&C, which is 64ish.

Yep, the 14 Bolt is a C&C at 63.5" wide. Super narrow, it's funny how close the u-bolts were to the back of the brakes. A pair of SRW hubs on the C&C axle will add 4" to the WMS, so 67.5" wide.... which should be a match to the front Dana 60 once the DRW hubs are replaced with new SRW hubs.

I believe the stock axles are 62 3/8" wide WMS, so the truck will gain about 2.5" width per side with the '79 one tons in SRW setup.

I'll need a lot of other parts for the SRW conversion for the front Dana 60; Hubs, bearings, seals, rotor, caliper, pads, studs, etc.


Hubs $239 - https://www.hillbillywizard.com/cucv-and-k30-parts/gm-dana-60-srw-hub/
Studs $4 x 16 - https://www.hillbillywizard.com/dana-60/gm-dana-60-wheel-stud/
Seals - https://www.napaonline.com/en/p/NOS27452?ref=MA==
Outer Bearings - https://www.napaonline.com/en/p/PGBPBR38?ref=MQ==
Inner Bearing (double check, says rear??) - https://www.napaonline.com/en/p/BRGBR101?ref=Mg==
Rotor - https://www.napaonline.com/en/p/NB_4885843?ref=Mw==
Right Caliper - https://www.napaonline.com/en/p/ADC2275XA?ref=NA==
Left Caliper - https://www.napaonline.com/en/p/ADC2275XB?ref=NQ==
Brake Pads - https://www.napaonline.com/en/p/SS_SS7081AX?ref=Ng==

I'll also need a disc/disc master cyl and it would be nice to add a brake booster at the same time.
 

Greg

Make RME Rockcrawling Again!
Admin
I'm still not 100% sure what do do far as the drivetrain in this truck... it would be nice to have it be a reliable driver, but I don't know that it needs the 6.0 LQ4 that I have. (That would be a better fit for the '67 Pontiac Bonneville.)

I don't care for the massive Rockwell T221 t-case, but the SM420 is rad.

I do have a stock LM7 5.3 with 140k miles on it in the shop. I could combine that with the 465 and 205 that came out of the donor truck. No overdrive, but 5.3's spin high RPM without complaining.

I'll have a 402 BBC in my hands soon, that would be killer under the hood buy I don't know how much work it'll need. ($$$$)

The 402 BBC, 465 and 205, plus the Dana 60 and 14 Bolt would make for a STOUT truck. 😎
 

Greg

Make RME Rockcrawling Again!
Admin
So the plan for the drivetrain at this point is to run the LM7 5.3 with the 465 and NP205 from the '79 K30, along with the D60 and 14 Bolt from the same truck. I think this will make the truck reliable, beefy and fun to drive. I don't plan on much freeway time with this truck, so the lack of OD shouldn't really be an issue. That said, I think the 5.3 will be just fine without overdrive, they don't mind spinning higher RPM either, in my experience. And the 5.3 should pull down pretty good mileage compared to the BB 402 or a 6.0 LS, which isn't a huge priority but would help making it a DD.

Running the numbers, with 4.10 gears, 33" tires and no OD the engine will be spinning right around 2,500 RPM at 60 MPH and 3,000 RPM at 70 MPH. If I ran 35's (after some lift) the engine RPM will drop about 200.

I have the engine, trans & t-case so this makes for a pretty easy upgrade. Figured I'd put together a list of the other related parts and costs.

Engine Management;

Clutch Parts;

Fuel Pump & Filter;
Misc;

  • Gauges - Would be nice to have a set of AutoMeter gauges, we will see.
  • Headers - Have a set of shorty headers in the shop.


Look like for around/under $2000 it's possible to upgrade the drivetrain, which isn't bad.
 

Pile of parts

Well-Known Member
Location
South Jordan
Cool! The only issue with that flywheel and old school transmission (and many claim it's not an issue) is that you'll only have about 2/3 contact between the flywheel and clutch disk. I debated running the same in my Jeep but decided I didn't want to risk slippage out in the rocks. I believe I reached out to @NYCEGUY01 as he had run the same type of setup you're referring to without issue.
You probably knew all of that and I think we even spoke about it already. Carry on - should be a fun driver!
 

NYCEGUY01

Well-Known Member
Location
Willard, UT
Cool! The only issue with that flywheel and old school transmission (and many claim it's not an issue) is that you'll only have about 2/3 contact between the flywheel and clutch disk. I debated running the same in my Jeep but decided I didn't want to risk slippage out in the rocks. I believe I reached out to @NYCEGUY01 as he had run the same type of setup you're referring to without issue.
You probably knew all of that and I think we even spoke about it already. Carry on - should be a fun driver!
Yep, We just did one on a c10 with the same setup and it drives fine.
Toss in a small cam before its in the chassis. May as well wake it up a bit.
The extra $ for a Holley Terminator would be money well spent in my opinion. The Holley software and interface is great.
 

Greg

Make RME Rockcrawling Again!
Admin
Cool! The only issue with that flywheel and old school transmission (and many claim it's not an issue) is that you'll only have about 2/3 contact between the flywheel and clutch disk. I debated running the same in my Jeep but decided I didn't want to risk slippage out in the rocks. I believe I reached out to @NYCEGUY01 as he had run the same type of setup you're referring to without issue.
You probably knew all of that and I think we even spoke about it already. Carry on - should be a fun driver!

I was looking at your thread not long ago and rereading about the amount of clutch engagement with a LS and older transmission. It sounds like others have done this with good success as well.

Being that ill be running a stock 5.3 and not wheelin it, I don't think the lack of engagement will be a problem.


Yep, We just did one on a c10 with the same setup and it drives fine.
Toss in a small cam before its in the chassis. May as well wake it up a bit.
The extra $ for a Holley Terminator would be money well spent in my opinion. The Holley software and interface is great.

We will see about an aftermarket cam, I wasn't planning on it but I'm usually the first person to recommend tossing the tiny, stock cam, especially in a 5.3. It ends up being a decent expense once you add everything up... and its already going to cost a couple grand.

I really want to try the Aces EFI system, it seems very similar to the Holley at a much better price point. It sounds essentially the same, you can tune it with the small handheld screen and do refined tuning with a laptop.

I want to run the Holley Terminator on my LQ4, it would be nice to be able to compare them back to back.
 
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