94 Gmt400

Guess I'll put everything here...
I've been trying to find a 6.2 or 6.5/NV4500 4x4 truck for a few years and never could find one near me but very recently I've found everything to build just what I've been looking for.

1994 K1500
4.3/SM465/NP241C
12 bolt 3.73 G80 Gov Lock

I'll be swapping in a NA 6.5 Detroit/NV4500/NP241C. Hoping it makes smoke by the end of the week.




I spent most of the day pulling the old engine and transmission. Perfect candidate for a Jeep. I've been looking at a $500 M38A1 that'd make the perfect victim,,,errr candidate.



My buddy Eric came over and decided to separate the TBI harness from the truck harness for fun. Huge mess. Like most of these trucks I see, the lower fender and battery tray have turned to dust. I'll try to clean the frame some and throw paint on it.



One of the negatives to this truck is the lack of hydro boost but I think a GMT800 unit will bolt on and they should be more plentiful in the salvage yards. For the time being, I'll attempt to use the vacuum booster as long as the vacuum pump works on the 6.5. To my surprise, the catalytic converter is still on the truck and intact so I'll chop it off and probably get ~$20 for it.

 

Managed to stab the engine and transmission yesterday. Yea I didn't feel like cleaning off the frame. It got a healthy coat of transmission fluid so that should deter any further rust for the time being.

The NV4500 is fairly tall and this truck sits fairly low to the ground.....problems were met with solutions. Hey Osha....



Originally the 6.5 trucks from the GMT400 era used a dual mass flywheel. I opted for a solid flywheel and used a LUK 04163 clutch kit and LUK LFW126 flywheel.
After installing the clutch parts and stripping the engine of the unnecessary junk I went to put it in and low and behold the driver exhaust manifold dumped right into the front diff. A quick search on the Google machine got me nowhere until I looked at the 6.2 flavor GMT400 exhaust and of course, it was a rear dump manifold as I suspected. I found a Dorman part number 674-470 and there was one in stock ~30 minutes away so I took off before the store closed to get it.

No bolts broke while removing the old manifold so they were cleaned up and slathered in anti seize.



I started to install the engine and luckily Eric dropped by to throw some bolts in the bellhousing after getting it lined up.



It made smoke tonight. The brand new starter I bought for the K10 and then put on this died already. It was working fine then nothing(solenoid probably). The 6.5 came with another gear reduction starter so I threw it on. The K10 gave up a few parts tonight like the radiator, alternator, fan, crank pulley, air cleaner, fuel filter housing, throttle cable, and a few other small bits.

 

It drives! This was a risky project since the engine and transmission were only said to be "good". 3rd gear has to be floated since the synchros are completely gone but other than that it seems alright. The truck has 3.73s and I can let the clutch out in 3rd and off it goes.

Needs a few things still but I'm pretty happy all things considered. Possibly going to a hydro boost unless I get an electric vacuum pump.

 

3rd gear and the 5th gear nut torque are really the only two things to worry about with a NV4500.
The transmission in my Tahoe has roughly 290,000 miles on it. 60,000 of those were on it when I got it. I retorqued the 5th gear nut when I first installed it.
My 3rd gear synchro is in rough shape. I have zero problems smoothly shifting it, but strangers tend to have issues.
I solved that problem by not allowing anyone else to drive it!

 

I learned all about the NV4500 when my old 97 12v Cummins destroyed its transmission two weeks after I bought it. Ended up buying a rebuilt transmission since most of the gears were trashed...

The NV4500 in this truck came out of a k3500 with a 454 and 3xxk miles. My buddy thought I was just shifting too fast but he agreed there're no synchros left.
I'll keep on driving until something gives.