Larry's 1978 K10

[Larry]

Thanks a million nitro_rat and Larry, great info! Also, very interesting on the TR-4050. Before they folded and combined into Four Wheeler Magazine (ending of an era), Petersen's 4 Wheel and Offroad had a short blurb on the TR-4050 but the info they had was limited to the specific swap they were completing. I didn't realize it is a direct bolt in for the NV-4500, the specs look nice and the gearing is much closer to the early GM NV4500 but without the non-synchronized 1st/reverse gears. I like the looks of the 3.11:1 2nd gear was well. I'm also happy to see the "Dexron III" fill sticker on the side. Not that its a big deal at the end of the day, but it always hurt to spend close to $100 on a gallon of Castrol Syntorq when refilling the 'ol NV.

Exactly! I was happy to see it uses a very common fluid as well. As much as I dig NV4500s they are very finicky and quite honestly, I don't think they are all that durable compared to say an old SM465 or even a ZF manual. The only thing a NV4500 really has going for it is OD and it shifts nice..... that's about it. They only became popular because there weren't any alternatives and I don't feel a Gear Vendors or any of those bolt on things are good alternatives in a 4x4

 

[nitro_rat]

The little two speed auxiliary transmission that bolts in front of the old 4 speed really makes shifting a chore and puts the transfer case shifter up under the seat, the gear vendors only works in 2wd. A trans with a built in overdrive really is the answer. I'm not overly impressed by the NV4500 either.

On another subject, it's the manual transmission that makes the Detroit Locker suck in your application! They really do act crazy behind a manual, weight and wheelbase don't help like they do in an automatic rig. One buddy of mine has a TJ with a rear locker and 5 speed, another has a Cummins swapped Suburban with a NV4500, they both handle equally poorly!

I used to run a locker in the rear of my automatic Suburban when it was 1/2 ton and other than the occasional bang in a tight parking lot it was seamless. Now that I've gone 3/4 ton I moved the locker up front and run the G80 in back, this combo is perfect for me!

 

[Larry]

On another subject, it's the manual transmission that makes the Detroit Locker suck in your application! They really do act crazy behind a manual, weight and wheelbase don't help like they do in an automatic rig. One buddy of mine has a TJ with a rear locker and 5 speed, another has a Cummins swapped Suburban with a NV4500, they both handle equally poorly!

No doubt about it. I’ve been preaching for years that manual transmissions exaggerate the bad habits of Detroit lockers whereas the torque converter soaks up the difference on an automatic.

 

[1976K5Chalet]

You will need a different brake pedal for hydroboost as the connection hole is in a different spot. Those pedals aren’t super hard to come by as there are may CUCV parts sellers out there or comb the junkyards for a squarebody with hydroboost. But, there will be a few bigger challenges as 1981 and later trucks used metric threads while 1980 and older had SAE threads. The CUCV hydrobooster will have metric threads but if your truck is 80 or older the steering gear and power steering pump will be SAE, so you’d have to have special hoses made or build your own out of AN fittings/hose. The second challenge would be if the NOS hydrobooster doesn’t have the firewall bracket already attached to it you’ll have to go buy a junkyard booster from a squarebody to get that….and the bracket is a PITA to change due to the odd nut and location of the nut that holds it on. Its not fun to get that nut on and off.

All this can be overcame though. I’ve done it a couple times. My K10 had to have special hoses made with the booster and power steering pump being metric and steering gear being SAE. I really wish I would have just swapped on a later metric steering gear at that time (or made my own AN hoses) because if I have a hose failure on the road it won’t be as easy as waltzing into Napa to get another.

Pedal shopping it is. I have all the AN fittings as i rather run with rebuildable AN fittings.
Pedal PN#355561 acquired thanks to eBay.

 

[zoomad75]

Hillbilly Wizard is a great site for used CUCV parts. They know what they have and charge accordingly, but usually have it. Plus as these trucks get to be found less and less in the boneyards, you might spend a lot in fuel going from yard to yard to get one. Buying from one of these guys despite the price is still saving time and money over chasing for it yourself.

 

[chilliwak]

Glad to see you posting again Larry. We all miss your cool builds and adventures. Cheers, Chilli... ?

 

[1stDeuce]

Larry, one thing to think about... Just having uber low gearing isn't all there is to it. I actually don't care for the 4:1 t-case in my TJ because it's only really useful in 1st gear to go really slow. If I want to move down the trail, I find that I'm rowing back to high range, as 5th gear low is only a tiny bit faster than 1st gear high. Back in high, I'm revving in 1st, or lugging in 2nd... I have no good gear spacing for the trail speed range that I run.

Sure, when I had 2.72 low range gearing in the T-case,I wished for a lower 1st gear a few times, but those times were a lot less often than the times I now wish I had a normal low range so I had a decent selection of gears for trail running.

If I were you, I'd think very seriously about an ORD Doubler. With the 4500, you have really wide gear spacing anyway, and 2:1, or 4:1 low should be good for trails, or for really getting your crawl on when you want to build your patience. I think you'd probably find that 99% of the time, you're in single reduction low. I suppose the Atlas 4 speed is another option, but it seems like you have plenty of gear splits with a "3 speed" doubler setup.

Just my $0.02. And welcome back, I missed you!!!
I also though for a minute that you bought that 6cyl blazer that I linked for you a while back. It got down to $1000, but I just couldn't pull the trigger on another project.

 

[1976K5Chalet]

Hillbilly Wizard is a great site for used CUCV parts. They know what they have and charge accordingly, but usually have it. Plus as these trucks get to be found less and less in the boneyards, you might spend a lot in fuel going from yard to yard to get one. Buying from one of these guys despite the price is still saving time and money over chasing for it yourself.

Very true. I ran the old GM PN all over the web and came up short so eBay had it brandy new. Next i'll try to find the little clips and such that keep the rod from falling off...and maybe a vacum brake assm to clean up and refresh and install the new pedal so its ready. Can't do much around here but i think i can get that done.

 

[MTCK]

Yes!! Bigassgas updates! Glad to see you are still running and wrenching on the rigs.

 

[shortbus4x4]

I just picked up a 03 8.1 today that has 15k miles on it. Bad news is it ran out of coolant and quit, it would still turn over though. Good news is it's from a C5500 so it has the A/C and brackets to stuff it in older vehicles and I only paid $500 for it. Hopefully it can be rebuilt, I'll dig out my engine stand and make a spot for it in my garage. Also got the Allison 2200 trans with ebrake with it for an extra $500.

 

[1976K5Chalet]

I just picked up a 03 8.1 today that has 15k miles on it. Bad news is it ran out of coolant and quit, it would still turn over though. Good news is it's from a C5500 so it has the A/C and brackets to stuff it in older vehicles and I only paid $500 for it. Hopefully it can be rebuilt, I'll dig out my engine stand and make a spot for it in my garage. Also got the Allison 2200 trans with ebrake with it for an extra $500.

I wish i could fall into a deal like that. Lol.

 

[Larry]

I just picked up a 03 8.1 today that has 15k miles on it. Bad news is it ran out of coolant and quit, it would still turn over though. Good news is it's from a C5500 so it has the A/C and brackets to stuff it in older vehicles and I only paid $500 for it. Hopefully it can be rebuilt, I'll dig out my engine stand and make a spot for it in my garage. Also got the Allison 2200 trans with ebrake with it for an extra $500.

That sounds like a decent deal! Depending what you plan to do with it, the Allison may not be a good fit. The Allison eats a lot of power and robs fuel economy out of 8.1s. You’ll get much more power and fuel economy out of them when backed by a manual

 

[shortbus4x4]

I'm thinking it's going in a Jeep m715 with axletech 4000 axles and 395 tires. In other words a big boy toy. I'm still up in the air if I'm going auto or manual transmission. Whatever I use will have to have the e brake on the transmission as I'm using the axletech t600 transfercase too.

 

[Deleted member 374434BT]

Larry,

Do you have any insight on the later commercial L21 454s with the coil over plug ignition? Supposedly they came with a forged crank and pistons. Ran from 98-01. Considering one for my GMT800 in place of the normal "Just swap a 6.0"

 

[Larry]

Larry,

Do you have any insight on the later commercial L21 454s with the coil over plug ignition? Supposedly they came with a forged crank and pistons. Ran from 98-01. Considering one for my GMT800 in place of the normal "Just swap a 6.0"

Not really. I’ve seen them around and they are often confused with 8.1Ls because they have coil near plug ignition. They also have a pretty desirable 24x reluctor wheel behind the timing chain crank sprocket that allows the engine to run on an 0411 P59 ECM just like an 8.1L or early LS engine, which means more tunability. A lot of guys are swapping that reluctor into L29's and replacing the 4x reluctor in order to use the better 0411 ECM. Aside from that, I’ve never been into one.

This is what they look like. Kinda look like an 8.1 but with an L29 intake. Also has a huge cam sensor in the dizzy hole

Kind of along these lines, I completed a TBI 454 to sequential MPFI (L29 454 intake) swap on my father in-laws 93 Sportside a couple months ago. This truck started life as a 4.3/5 speed where back in 2012 I swapped in a 454HO (Gen VI based) left over from my K10 from when it got its 8.1 back in 2008. It was a boat load of work going from TBI to later model sequential injection on a relatively modern truck and still try to maintain everything in factory working order such as the ABS and Cruise control but it turned out great. Runs like a raped ape too! Yes, a modern LS engine would be faster but LS swaps are becoming as common as bellybuttons plus the idea with this Sportside is to be a 454SS clone with a Sportside bed twist.

TBI 454 it ran from 2012 to 2019.

During the surgery over winter 2019/20

After…. It totally came out look like it was born with an L29 under its hood