Some time back, I was asking ?'s about this Cummins re-power. There was consern that the GMC 350 turbo trany would not hold up the Cummins. I would like to tack this time to let everyone know that it has been in there now for 8,000 miles. I have a boat that is 6,200 lbs on the scales with the trailer. The 79 re-power pulles with no problem. No I don't let of the pedel for it to shift. It shifts tight with no sliping and it runes cooler than it did with 468. Keep in mind, I did order this trany from North Carolina, With cost of $1,400. There are a few things I did on the trany for adjustments. The 350 needs vacum to shift. I removed the pod stile pumps and put a vain pump in place. Then I removed the old vacum brake pod from the fire wall and put the hiydero brake system in. (sory about all the bad spelling) Now all my vacum is used for the dash and the shift. I also adjusted the pod on the side of the trany to get the desired shift timming. If you want it to wait longer between shift's just turn the screw in more, as if you were to tighten it. The screw is located inside the pod. Just remove the hose and insert a small regular tip driver and turn till it start to get resistance. Then drive and make your adjustments as needed. Iv'e pulled as much as 4 ton of sand and rock in the bed of the old re-power and she's still going strong. I have a list of every thing I got, where I went to get it, the price, and what I did to make it a simple job for any one. So don't be scared to do it your self. There's nothin to it, and she'll run better then you could ever think posible.

 

Thats great to hear!! Glad its working out for you

I think that just about any tranny that is built right can and will handle the power of a CTD, I am pretty sure that a stock 350 tranny would hold up too long though.

Couple questions.

1. Where or what adaptor did you use to attach the tranny to the engine?
2. What about a flexplate?
3. Whats your top speed or say what rpm's are you running at say 65mph? What are your rear end gears?
4. What kind of fuel milage are you getting?


thanks, Aaron

 

What did you have to wire up on the Cummins?

 

The gears are 375. All the things to re-power the trany case were from Cummins. They put the Cummins in bread trucks in the mid 80's. Flex plate to. You'll need a diferent starter. The converter needs to be an alason coverter. I dont drive it easy and I still get 16-18 in town. Tp speed is 85 flat on the floor. About 2,600 RPM. At 65 it runs about 1,900 RPM's. There was nothing to wier it up. It came from a 91 Dodge. I had a alternater & starter company re-cofigure the Dodge alt to a two wire (not including the ground) just like the 79 was. Then just run the old ignition power wier to the fuel switch on the back of the injector pump. Don't get cunfused between the timming advance and the fuel switch. The timming advance is on the side of the pump, and will only need a suply if it gets below 0 much. And the starter wiering is the same, but I would run a nother ground to the stater it's self. Just put it under one of the stater bolts. O, I almost for got, you will most likely need a 1/2 inch starter shim, and you will need to modify it to fit.

 

Did you hook up your grid heaters and the fuel heater for cold weather starts?

 

Not both. I only used the grid heaters. I doesn,t get that cold in nothern Missiour. The coldest I've seen is -10.

 

What did you have to do to hook the grid heaters up? Where there any relays or anything that had to come off the dodge donor truck?

 

I thought of that but I wanted to make it as simple as posible. I used a push button switch to activate the contacts. I hold the button for 5-8 sec. then release and start the truck. They don't need used as much as the dodge used them. It will start at 30 degrease without them.

 

Yeah I know it hardly ever really needs them. Did you look into keeping the auto cycle at all or just didn't want to mess with it at all?

 

Well I did both, but it saved a days work to just use the switch. If you want to go through the work, thats fine. The fastest way to do it would be to find a gm truck that has or had a ratle box and use it's harness,dash cluster, musle,and so forth.

 

So the timer and switch is in the dodge harness somewhere? if so I would just go the route you did.

 

It is never found in the same place in the dodge. The cummins was allways an after thought from the start till 94. In 94 they started to incorperate the idea of the Cummins into the dodge, to be a good saler. Before the were re-powered just as I have done but on a lot bigger scale. The trucks had been manully re-fited to une the Cummins. And if anyone doen't beleave me cut open any dodge harness and see for your self. It's a mess in there. Thus is the resone for dash, and harness fire's from 88 & a half - 93. Cool

 

There should be less electronic stuff with the diesel than with a gas motor especially fuel injected, I don't know the exact year they went to a throttle body though.

 

The 88 to 93 used a IAT sensor to trigger the grids. All you have to do for
auto-cycle is run from the IAT to the solinoid and feed it with the key.

It am easie

BUT, I agree with the axle you hardly need the auto-cycle.

In fact I have removed mine all together.

 

Say while you all are here I would love to move the truck leftovers out. If you any one that needs parts off it or the hole thing, it's realy getting in the way.