PDA

View Full Version : 6.5 to duramax conversion


muddstopper
12-02-2006, 04:51 AM
I have been thinking about trying this for a while. Has anybody here put a duramax in the place of the 6.5 in a older model 4x4 chevy truck. I have a 95 dually that is getting a little worn and cant think of buying another new truck right now. Thought about buying a duramax/allison out of a wreck 4x4 and trying to fit it in the old truck. Just need a little imput from someone that has done it or knows someone that has done it. Im just not sure if I want the hassel with the electronics. I need to make sure I get everything from the doner truck that i need on the first trip to the salvage yard.

tnmtn
12-02-2006, 07:33 AM
hey mudd,
you might check on the www.thedieselplace.com they have guys there that could probably answer youur question. good luck with it.

muddstopper
12-02-2006, 11:51 AM
Thanks for the link. I havent found the conversion info yet, but I did find out what was ailing my 6.5!!! The fix is a lot simpler than a conversion I am sure.

mag360
12-03-2006, 01:25 PM
The 12 valve cummins conversion is probably best for your truck.
You won't need to worry about swapping in a new cpu, and you can get similar power for alot less cash. Also, an nv4500 trans should be easy to find mounts for since gm used these in a lot of the 2500 and 3500 series trucks.

muddstopper
12-03-2006, 02:11 PM
I hadnt thought about a Cummings conversion, might check it out. I guess a quick trip to the salvage yard and just findout what is availabe is in order. My truck has the Nv4500 tranny already. Its about Junk, I go thru a clutch a year, syncronizers shot. Ford, Dodge and Chevy. all used this transmission in their trucks for a few years. Dodges had the lowest first gear, of the three manufacturers. 4wheelers loved getting their hands on the dodge trannys for rock climbing.

I am really wanting to go with the later model Duramax/Allison combo. I already own a 4500Duramax truck and love it. I have to start and stop so much ( on steep roads under load) is the reason I go thru so many clutches. I think the Allison, even tho it might cost more at first, will save me money longterm. I usually end up spending around $1000 everytime I have a new clutch installed. A couple of years would pay for the Allison. I like my 95chevy truck. It aint beatup or rusty, interior is clean, I cant see spending $40,000 to replace it when a late model engine conversion will serve me well.

Gravel Rat
12-03-2006, 04:39 PM
The cheapest option is a Cummins conversion if you want to replace a old 6.5 trying to drop in a duramax isn't worth it. Light trucks don't last forever we are lucky to get 10 years out of one. A 95 is getting pretty old I don't know if you really want to spend 10,000 dollars on a engine repower. To do a Cummins swap plan on 6000 dollars a duramax swap would be a easy 10,000.

If the truck has 200,000 or more miles on it sell the 95 its not worth beating a dead horse. You NEVER save money constantly repairing a old truck a new truck may cost you 40,000 but it will last you 10 years. Spending 10 grand fixing up a 7000 dollar truck still makes it a 7000 dollar truck.

Trust me I have seen people dump tons of money into old trucks that never gained they lost its cheaper to buy new.

Dirty Water
12-03-2006, 04:56 PM
There are 3 rebuilt 5.9 12 valves on e-bay right now for under $5k.

Tim Wright
12-03-2006, 06:50 PM
The cheapest option is a Cummins conversion if you want to replace a old 6.5 trying to drop in a duramax isn't worth it. Light trucks don't last forever we are lucky to get 10 years out of one. A 95 is getting pretty old I don't know if you really want to spend 10,000 dollars on a engine repower. To do a Cummins swap plan on 6000 dollars a duramax swap would be a easy 10,000.

If the truck has 200,000 or more miles on it sell the 95 its not worth beating a dead horse. You NEVER save money constantly repairing a old truck a new truck may cost you 40,000 but it will last you 10 years. Spending 10 grand fixing up a 7000 dollar truck still makes it a 7000 dollar truck.

Trust me I have seen people dump tons of money into old trucks that never gained they lost its cheaper to buy new.


I have been mulling over a similar issue. I would like to pick up a new GMC 2T with a duramax, and yet keep my old dumper.

So with the numbers above, you have a $40k truck that will last you 10 years. At that it will still cost you $333.33333333333333333333333333333 per month for 10 years. Thats a chunk of change to count on every month for 10 years. It might be cheaper to drop a new engine in the old truck. Once the new engine is in, other repairs are going to be normal to any vehicle after a certain number of miles regardless as to whether it is new or not.

Tim

Gravel Rat
12-03-2006, 07:49 PM
The Cummins is a good option for Chevy as the 6.5 is a turd engine definatly not one of Chevys finest. There are adaptors that you can get for the Chevy engine to bolt to what ever transmission you want. The only problem with Cummins is they are loud engines.

muddstopper
12-05-2006, 06:55 PM
Gravel, are you saying my old Chevy is worth $7000???? Sold, I will even take Canadian.LOL. All bull aside. I know what you mean about old trucks nickel and dimeing you to death. I put about 8-9000 miles a year on my trucks. My 2005 4500 only has 9000 miles on it and its a year and ahalf old. The problem with buying a new truck is where I take it. Always a dozer on standby to drag it in and out. Its hard to pony up $40 grand and watch it get beatup in the brush. Thats why I prefer just fixing my old truck. Someone mentioned the cummins on ebay for $5000. Well, that might get you the engine, but what about the radiator, alternators, electronics and anything else you might have to buy, including an adapter. We are getting close to the duramax conversion money wise if I buy a complete system from a wrecked truck. It will last me as long as a new truck for a fraction of the cost of new. And I wont have to kill the engine everytime i drive up to a drivethru to order a burger. I still dont know just how well the duramax will fit in my old truck, but I know i will have to do some modifications if I go with another engine, so no big difference there in difficulty of the install. Anyways, I am still weighing my options. I have found a couple of ford 7.3 trucks and just might buy one of them and sell my old truck. I know I will like the straight axel in the fords better than the aframe supension of the chevy. Still have the engine noise tho.

tnmtn
12-05-2006, 08:57 PM
i had checked into a cummins conversion for my 94 F350. as i remember the shop quoted around $10,000 for them to do the install with a reman engine. i was trying to get more power for the truck and then decided to go with the new Chevy. the Ford is still running and i use it for lighter jobs.

muddstopper
12-05-2006, 09:54 PM
I did a little e-bay searching and found a few of the cummins as well as duramax engines. Late model stuff was similarly priced. engines only, with ecm's ect. around $5grand. Did find a couple of complete duramaxes, including trannies and transfercases at $9-$10 grand. I think I will just put a new turbo on my old truck for now, and keep looking for a better truck.

Albemarle Lawn
12-07-2006, 12:21 AM
but for that old Chevy....

Just drop an Carbureted 350 in it with a towing cam and L-31 Vortec heads (Edelbrock makes a manifold for a carb on Vortec heads). A turbo 400 trans would really complete the deal nicely.

You'll have more power than that 6.5 turd motor. I have an 89 Suburban, fuel injected motor crapped out, dropped in a Vortec 383 stroker. Good mileage, about 14 MPG, and butt loads of power.

$3000 and you could have a sweet brand new motor, with brand new carb, and new rebuilt transmission, and new exhaust.

muddstopper
12-07-2006, 03:03 PM
If I wanted to go gas, I would use the 454. I have a 3500 with the 350 and turbo400 tranny and 4:56 posi rearend. Aint worth a $#it for towing.It Will stall out on steep hills. Now if you take the 454 engine, or 427 tokkinamas (sp) engines, with the 475 turbo tranny ( truck automatic), then you would have a good gas engine 1ton truck combination. Never take a mouse to do a rats job. I happen to own a old bus that has the good tranny, I just might look for a good bigblock. I believe the 6.5 bellhousing will even bolt up to the chevy gas engine. I know the flywheel will interchange. Of course i would end up looking for a divorced transfercase for the 4x4 If i went automatic, but i could just leave in the nv4500 manual tranny.

TLS
12-07-2006, 03:55 PM
Sell the 95 and get a good used big block of the same approx age. People are giving away the big blocks with the rising gas prices.

Gravel Rat
12-07-2006, 04:06 PM
I wouldn't want to put a 350 in a 1 ton dually talk about underpowered you really need a 454. Or just sell the truck and buy a truck with a 454 or Duramax.

muddstopper
12-08-2006, 09:03 AM
my 6.5 has turbo problems, worn tires, growling tranny, roaring rearends, that are to high speeded to be good at pulling. .But it sure do look good, and chevy does have class. Cant say that about the fords or dodges.












































(hint, I just posted that to see how many fish I can catch)

muddstopper
12-08-2006, 09:27 AM
I thought I would post a little history on the 383 stroker engine. Of course no one knows for sure, but Randall Twiggs probably built the first 383 stroker chevy engine. He raced late model dirt in the 60's until even now. there was a unlimited engine rule in effect but they had a cubic inch limit that prevented chevy from running the 400 small blocks, but let ford and dodge run the 390,383 engines. You couldnt bore the 350 chevy enough to compete with the bigger ford and dodge engines. To make the 383, Randall, took a 400 crankshaft and turned down the mains to standard for a 350 engine. this meant the 400 crank would fit in the 350 block, but no one made any pistons with the correct pin height to allow running the standard 350 rods. This meant using the shorter 400 rods to keep the piston inside the block. This also meant he could use the standard 350 pistons. Now there is a downside to this combination. 400 rods are not as beefy as the 350 rods and had smaller rod bolts so these engines where subject to throwing rods, but they made goobs of power while they lasted. Another drawback with the shorter rods was that they reduced engine torque and also changed the rod angle. the increased rod angle meant excessive wear on the side of the engine bore and pistons where subject to break off the skirts. Of course nowdays, you can buy all kinds of high performance parts to build the stoker engine, stuff that will actually hold together, but before the 383 stroker became popular, Randalls cars won many races in Ga, Tenn, and Nc. Randall never drove any of his cars, but even today, he is building dirt track cars and they are still winning races.