Which swap is cheaper and worth doing

[Chris Guthro]

Ive been hearing lots of bad stuff when people are asked swapping a 6.5 into the squares, how many people installed the 12 valve cummins in one? and what would be the total cost of doing one? is finding an older dodge parts truck the easiest way to go ab out it?

[Pyrotechnic]

6.5 is probably cheaper because it was designed to drop right into SBC/BBC motor mounts and bolt to the same transmission. The buying price on one is also much cheaper.

Cummins 4BT and 6BT stuff is very expensive. Seems like you're better off finding donor truck with a good motor and selling off the rest when you get done taking what you need. I don't know why, but the price seems to sky rocket when the motor is sitting on a pallet by itself.

Of course, you really can't compare the light duty 6.5 to the medium duty 6BT. The 6.5 was designed as a light duty diesel and is good for moving 1/2 to 1 ton trucks around. The 6BT is something you'd find in a medium duty 2 ton truck and industrial applications, that got put into a light duty truck.

[92GMCDriver]

A local scrap yard owner has the body of a square on a dodge chassis, cummins and all. looks pretty good imo.

Edit: i believe the chassis is a late 1990's style

[Chris Guthro]

Yea, from what im reading the 12 valve has limitless potential! and just by swapping the fuel pump to the newer generation is something like 70 hp! seems like it would take over $2000 to squeeze that out of a 6.5! Im gonna keep an eye out for a cheap donor truck! and see what happens, what all is really needed to be done to it to get it in a 4wd 3/4 ton?

[67_SS396]

Go 12 valve P pump and don't look back. My 97 Dodge pulls like a dream and I've got less than 500 in mods. I can pull my gooseneck loded with two rock crawlers (over 20K) total weight and run 80 or better while getting 12-15 mpg.
Posted via Mobile Device

[81chevys]

4 bt ALLL The way.

I met a guy with a k5 and "military axles" ... he swore up and down he got 30mpg on diesel. but he said it cost like 5k+ to complete the swap.

[Chris Guthro]

Im not gonna do th 6.5 seems like alot to rebuild one to handle anything even NEAR 275-300 horse, where a cummins can get that by just changing the pump. Anyone have any links to anyone who sells the mount kit or crossmember? Ive tried searching but havent came up with any links yet. Is there a certain year 12 valve that are better then others?

[81chevys]

I forgot to say bt4. I don't really know about valve count on the diesels. That bt4 was very pretty peppy.
Posted via Mobile Device

[STOCKISH]

Put a P-Pumped 12 valve in it and you'll never regret it!

[67_SS396]

A 4BT is cool in a little rock crawler, like a sami, but I wouldn't consider it for a fullsize. Any of the 94-97 12 valves will be good, 97 with a stick will have the 215 hp pump and provide the most bang for the buck. 93 and older are VE pumps and are more limited to what power can be made.
Posted via Mobile Device

[b454rat]

Tennessee Diesel Conversions sell the motor mounts and crossmember so any year 6BT will bolt in. The kit is $500 last I checked. I have them for my crew, needed a crossmember anyways, and plan on putting a 6BT. I wouldn't put a 6.5 on my lawn mower, won't have enough power to mow and go up hill at the same time. 6BTs with the P-pump (94-98 I think) are the best engines to go with. No electronics, sky is the limit as far as making power goes, also depends how deep your pockets go. but that is only for crazy power levels.

A free flow exhaust, large by huge air filter, a fuel plate (or modified stock one) and some tuning, can take a 160 horse, 400-ish ft/lb of torque, and make it 260 horse and over 600 ft/lb of torque. Can a 6.5 do that?? Can a 6.5 in a small Freightliner FL70 with a 7-speed pull a set of doubles??

[chevyman95]

cummins hands down

[Chris Guthro]

Yea Im not lookin for a sky level hp numbers, i just want something thats got good economy, good power when i need it. And a Nice little rumble! I have a lead on a 95 12 valve, its the whole truck, 5 speed, its been gone over before, he only wants 1500 for the whole truck. good deal?

[lindstromjd]

As much as I would have liked to see the 6.2/6.5 in your truck, yes, $1500 for a full truck with a 5.9 with a 5 speed is a killer deal. Jump on it.

[b454rat]

That is a killer deal. The tranny's are just about half that. In stock form 6bt's make more torque than any other GM engine out at the time. With the 5-speed and some highway gears, you should be in the 20s for MPG. But the power is there if you need to tow/haul something.

[67_SS396]

My 97 dodge empty gets 20mpg. Loaded with 14K behind it, running 75-80, I get 14-15 mpg. Go p pump and don't look back.
Posted via Mobile Device

[Chris Guthro]

So are the VE pumped cummins worth doing as well? because the guy hasnt gotten back to me about the 95 yet! I kind of feel i want to hold out until i find the right generation. I dont care when it gets done at all, i just want to have a cummins powered chevy some point in my life, and now that I have the whole thing stripped and am replacing everybody panel and everything on the running gear, now is the time to do it!

[b454rat]

VE pumped 6bt's aren't bad, just not as "tunable" as the P pumps. Meaning you can't do as much to them or get the power of them. But they are quieter and get better fuel economy than a P pump.

Kinda weird, not that I'm looking for one, but all I've found is P pumps, never see VE's where I am.

[Chris Guthro]

on a scale of 1-10 how hard is the swap? is there kits to make a chevy tranny work with the cummins? like the sm465?

[b454rat]

I haven't done mine yet, so I can't say how hard. But these motors are like old Chevy's, one wire to get them to run. Really don't need that, it's for the fuel solenoid. It's hard to say what would be the hardest having not done it, can't really comment.

You can get kits to bolt up just about any tranny to these engines. If you can find an old Frito Lay or similar truck that had a 4bt, the flywheel, adapter, bellhousing and starter all interchange with the 6bt. Some of those Frito trucks are GM chassis, had the 4bt swapped in and used either the TH400 or SM465. So you could use either of those on the 6bt, but especially on the 400, don't expect to last long. The problem using the 465 isn't the strength, it's the clutch. Even the biggest/strongest clutch still isn't strong enough to take the torque of the 6bt. Plus not having an OD, will be screaming driving down the road. Course of you have highway gears might not be bad. Best bet would the NV4500.

[Chris Guthro]

So if i found a mid 90s p pump and a nv4500, is there any wiring to the tranny? and what mods would need to be done to tranny crossmember and will the driveshafts be different?

[b454rat]

Only wires off the tranny should be for reverse light, and possibly speedo or VSS, not sure what Dodge used. Not sure where the tranny mount would go, but think it would be easy to mount to the cross member, then slide the cross member back or forth till it lines up. Hard to say on the driveshaft, depends what type of tranny that was in your truck, and if the 4500 has a slip or bolted on yoke. At this point, it would be a minor detail!!!

[Chris Guthro]

Yea thanks for the help and info! But i just want to find out everything before i go about and attempt this. Seems like a straight forward swap but a lot of little stuff that may end up kickin my butt

[b454rat]

There always is!!!! I'm not gonna be able to do my swap this year, but still reading up on stuff like this so most of the bases will be covered.

[67_SS396]

Up to 98, the speedo is mechanical and in the tailhousing. After that, its a sensor on the rear pinion. A VE pump can make decent power, but wont compare to a P pump. You can still get 700 ft lbs and 350 horse pretty easy. The VE will have a getrag trans and the P pump will have a NV4500 which is hell on fifth gear. It's a real sorry design for fifth, but other than that, a good trans. Stay far away from the autos. You need OD because they don't turn many rpms. The VE with the pump modded will still only turn about 3400-3600 without a lot of work. From the sounds of what you are wanting, you should be happy with either engine. If you have a torch or plasma cutter and a welder, you can make anything fit with a little time and effort.
Posted via Mobile Device