94 C3500 350 converted to a 96 C3500 6.5

[tanman_2006]

Well I'm about fed up with this 350, it's not terrible running but in the fact that I add a qt of coolant and a qt of oil every 5 k says it needs work, heads at the very least.

I have a buddy with a 96 C2500 single cab fin F with 60k on a GM crate engine from 2010. My thoughts are put the cab and engine on my 94 C3500 5 speed chassis. Is it just that simple? His truck revs to 2500 with and pedal, if you let off it bounces between 700 and 2500

 

[tanman_2006]

Another option is vortec heads or a 383 crate engine. That still leaves me with no ac, butchered wiring, and a cab with rot at the top of the windshield.

The cab swap would give me a clean cab, newer dash, ac, and cruise. I could still have 2 running trucks at the end if desired.

 

[THEFERMANATOR]

Fyi, vortec heads and 383 are not simple drop ins for a tbi. You had better plan on some datalogging, and working with a tuner if you decide to go that route.

 

[tanman_2006]

That's the plan and is noted. So chalk up more reasons to body swap to the 96 which can get proven KOJO tuning and an ATT on its GM Goodwrench Optimizer.

Now, the biggest question for me is should I use 96 brake master and booster or the 94 master and booster? What does the ABS need to function. Will the 96 tail light harness reach the rear of my longer cab and chassis frame? Other than a tuning change what do I need to run the 94.5 NV4500 trans (make a harness, splice in the 94 harness)?

 

[Burning oil]

Aren't fuel tanks different? as far as sending unit/pick up go's? I know it will be 26 gal vs the 34.
You going DB2? or swap wire harness?

 

[tanman_2006]

Swap entire harness.

My cab and chassis tank is behind the axle and is only bout 30gal. Yes it will take a different pickup and metrum rod. Pretty sure the 96 harness with a 96 pick up will be OK but the harness won't reach to behind the axle I'm pretty sure.

 

[tanman_2006]

The 350 isn't sounding to hot right now. Oil pressure dropped, no power at all, and is knocking like a sob and speeds up with rpm.

 

[deejaaa]

i would delete ABS. not a good design for our trucks.
is the newer engine an updated block?

 

[tanman_2006]

Yes, it's a Navistar block with under 100k on it according to what the previous owner told him.

 

[THEFERMANATOR]

i would delete ABS. not a good design for our trucks.
is the newer engine an updated block?

Guess I'm in the minority, I always liked the kelsey hayes 3 channel system. It was used for a decade virtually unchanged, and I don't believe there was ever a recall involving the abs unit unlike many bosch units of the day.

 

[tanman_2006]

Still Haven't laid hands in the truck. Won't start without ether

 

[tanman_2006]

Ok so truck has a knock in the bottom end, sounds like a rod bearing or wrist pin type knock. More like a tap tap tap but all the rockers test out and push rods feel tight and I don't have enough play to hardly get a feeler under any of the rockers. Knock gets worse as the engine warms up.

Had a blown gasket in my throttle body, resealed it and it held fuel pressure just fine under load and pulls good if you can ignore the knocking.

So now that I have to make a serious repair (more than heads) this diesel swap is sounding better and better.

What am I looking at to get this thing going?

Oil Cooler lines
Clutch/flywheel
Harmonic balancer/pulley
Tank Sending Unit (or can I modify the 350 sending unit?)
Motor mounts
Pmd extension

I would like to build a budget to compare this to a crate engine.

Thanks

 

[tanman_2006]

Guess I'm in the minority, I always liked the kelsey hayes 3 channel system. It was used for a decade virtually unchanged, and I don't believe there was ever a recall involving the abs unit unlike many bosch units of the day.

Mine have always worked, never felt the need to change more than better quality than oem

 

[Husker6.5]

My 94 C2500 C&C has the 34 gal side mount tank, always wanted to add the rear 30 for increased range when I used to work way out in the boonies, like Phillipsburg or Norton, KS. Check your C&C rear wiring harness. If it's like mine with the service body on it, there's about two extra feet of harness coiled up and tucked into the driver's rear corner of the frame where the rear crossmember joins.

 

[tanman_2006]

They didn't make a C2500 cab and chassis, just a factory bed delete. A little different than a C3500 Cab and Chassis. The fuel gauge wires will have to be spliced and repinned for the diesel sending unit in the rear tank, if I want to add the mid ship 20 gal tank later that wiring will have to be worked out also.

 

[Husker6.5]

If they didn't make it, then why do I own a '94 C2500 C&C? The frame is NOT set up for a pickup box, it is set up for the framerail width for mounting an aftermarket flatbed/service box and has the mounting points for hanging the 30 gallon rear tank (and my Rawson Koenig service box has a second filler port for connecting to the rear tank if it had one) and does have the extended wiring harness for if a ten foot service body was mounted instead of an eight. Furthermore, when my ECM was toasted, the local GM dealership had to special order its replacement based off of the P/N because it was for commercial vehicle use and has a speed limiter programmed into it at 82 mph whereupon it defuels - regardless whether it is in OD or 3rd. So, @tanman_2006 , I don't really want to argue with you, but it is what I own.

 

[tanman_2006]

Not trying to argue but never seen one that wasn't a bed delete.

Mine doesn't have any extra wire coiled up. The harness goes straight to the fuel sender and the tail lights go straight to the junction box then to the tail lights.

Alot of bed manufacturers build them to fit any truck, ford's had dual tanks.

 

[Will L.]

Yeah, they made them. We did some when I owned the truck equipment company. Price was low enough on them that We bought one and made it a parts runner truck with a little flatbed on it. They just didn't make a lot of them. The payload on a 3500 can be ramped up pretty easy, but not the 2500. That why they didnt sell.
@Husker6.5 , you might want to weighyour setup. I was an RK dealer, and their beds are heavy as hell. Well made, but heavy. It has been a lot of years, but I don't remember a full body(required for dual tank filler necks) that didn't almost max out the 2500 by itself. If it is a full height, or covered bed version, you are overweight as soon as you put any tools in there.

Just be careful.

 

[Husker6.5]

Mine is an "HD" (1 ton leaves in rear). The RK is an 8' open top six door. I scaled my truck "empty" (loaded with my tools, ladders, sheet metal brake, full tank of diesel, and me) at 8200 lbs one time and with a load of a house full of 12 replacement windows, a patio door, two entry doors, three rolls of aluminum trim coil, interior wood trim, some assorted framing lumber and two rolls of insulation scaled it at 10,300 lbs.!

In Nebraska, Commercial Truck license plates are issued automatically with a 3 Ton total vehicle weight. "Dry" I was already just over 4 Tons. For the extra $250/year I plated it at 6 Tons, cheap insurance because if you were ever scaled at more than your plate rating, the fine was $350 per 1000 lb unit over, so if you were 1001 lbs. over your plate rating, $700 fine.

Then there was the towing. 23' dovetail with a Dodge Grand Caravan across Iowa. Two yards of concrete in a U-pour-it trailer up and down the steep hills of Omaha. 23' dovetail with a 730 Bobcat with bucket and 24" auger attachment AND a full pallet of 60 lb bags of Redi-mix concrete around Omaha.

 

[GM Guy]

@Husker6.5 would it be weird if I asked you to send nudes of your truck? (frame pics )

I have a factory box off C2500, and the frame is still a pickup frame, only thing that was weird was the wiring, slightly different than the pickups. I currently have a box on it.

Do you think yours might have been a C3500 converted to SRW? What is the rear axle width?