350 Repower

[teking]

Don't kill me for asking questions I know have been asked a million times!!!

I've read the web and this site a bunch the last two days or so and the options are too many to ponder.

My goal is to maintain all the stock functionality and look. Everything I can i.e. transfer case, winch, blackout lamp , etc. But to drop in a more reliable drive train.

I'd "like" a 350/divorced NP205 w/ some manual tranny. All installed w/o cutting, violating the stock body and frame. Basically bolt right in. Is this possible? I'd also like to retain all the stock wiring (the harness is brand new).

Considering disk brakes from UglyTrucking.
Cowan set of wheels (I really like them)
Already have gears changed out and Selectro locking hubs.

Is all this possible? If so can someone post a "recipe" ... parts list? A lot to ask I know. But I'm thinking of dumping my vette, getting a new truck and concentrating on my M715.

This is what it looks like now ... Like to keep it as unmolested as possible ..



Before ... LOL

http://www.tomnlisa.com/files/M715/running_no_body.AVI

[kevin]

That's a nice looking truck !

Once you start swapping the tranny and x-fer case the PTO connection will need some thought. I'm unaware of any conversion motor, tranny or x-fer mounts. They will need to be built

When I swapped my motor,tranny and x-fer there are a thousand things to think about. and a hundred more that will pop up while you do the conversation.

I would get a mated motor, tranny and xfer and make new mounts. it will be easier and cheapest. Divorced x-fers are just more things to think about.

But it is your truck do what feels right and have fun. It does sound like a good winter project.

Now if only I can get my motor sold I can start on my project of swapping from a 454 to a 4bta!

[teking]

What if I keep the stock tranny and use a Novak adapter and Novak engine mounts on the 350? Will that and a divorced Dodge NP205 drop right in?

That shouls also allow me to keep the winch ... correct?

[Barrman]

You can put in just about any gasoline engine without ever using the cutting torch, or saw or nibbler or anything else besides a drill. Maybe a hammer, but maybe not. The same goes for a 6.2 diesel or 4BT diesel.

The V8 issue we all have had to deal with is the exhaust. Short dual exhaust exiting outside the frame rail just behind the cab, long dual crossing over or under somewhere in front of the fuel tank or long single with a cross over somewhere in front of the fuel tank. Inline engines gas or diesel don't have that extra worry and can pretty much run stock exhaust or stock looking exhaust.

I went gasoline big block and love the power. Most everybody that hears the truck though knows it is not stock. A gasoline v8 is also going to probably need better cooling than the pretty small 40 year old stock radiator.

The diesel M715's I have been around confuse people. Is it stock or not? People are used to military vehicles being diesel and don't give a clattering M715 a second thought compared to the rumble of a V8 which they know isn't stock.

Be carefull what back spacing you get on the Cowan wheels. I have seen two sets on two different trucks both running Michelin tires have some rubbing issues because the back spacing is off compared to what it should be. I also don't think he is having them built anymore. Give Marsh a look as a back up.

Something else to remember when planning a swap is the 5.87 gear ratio. With those kind of gears, top speed is more an issue of engine rpm than horse power. Up to about 70 mph, then the effort of pushing a brick through the air means torque is what you want. Look for and build for torque.

Acceleration is really a matter of how fast can you shift gears. I trippled my power by putting in a 396. Yet, I doubt my 0-30 times are much different because I can't shift the NV4500 fast enough to make use of my doubled rpm range or more power. 0-60, big difference because once I get into 3rd, I can just let the big block run.

I think I actually made the truck less trail worthy with the swap though. Mainly due to carb issues and the fact that the 396 doesn't have much power below 1200 rpm while the stock engine is good down to around 400 rpm. That is a big difference when you have 4 adults in the truck riding trails at a slow speed and don't want to bounce anybody out or get any air going over obstacles. EFI would probably make it at least equal to stock if not better.

We had 3 M715 or M725 trucks at the 2008 Fe in Colorado. 1 stock, 1 small block and 1 big block. The stock truck never had to adjust timing or carb or anything else for the 7K altitude we were camping at and the up to 12K altitude we drove to. Us V8 guys did. The stock truck grunted right along using the 5.87 hears and great granny 1st gear while us V8 guys had to shift around to keep our rpms up do to power loss at altitude and over heating issues because of the thin air. Stock truck just kept on coming with no worries.

As with another poster in this thread, I am planning to go diesel. I can do the entire swap for less than a good EFI set up for the 396. As pointed out above, 65-70 mph is really the practical top speed of these square trucks and OD with a diesel will still get me there. A 6.2, 4Bt or 6BT will all have more grunt at trail speeds than my 396. Cooling the engine will not be as critical at trail speeds because diesels don't make that much heat at idle compared to gas engines. A side bonus is that my 9-11 mpg will probably go up to at least 15 if not more. Use a turbo and things just get better.

If I was starting over with a stock truck that needed engine work and I decided to swap instead of repair. I would go 4BT to either a NV4500, 3053A or 4L80E. However, since I couldn't afford a 4Bt when I did my swap and don't have the money for one now. I would end up with a 6.2. Which is what I am going to have in the near future.

The really sweet set up would be a 1991 6.2 or 6.5 turbo with the available that year only. 4L80E and a married passenger side drop NP205. A built 700R4 married to a 208 would be just about as good just no PTO port like a 205.

[Barrman]

Forgot the wiring.

You can do a gasoline engine and not change a single wire on the truck. The stock temp and oil psi senders will screw right in. Add a 3 Ohm resistor to your coil and it will work off 24V. You will need a 24V starter though.

EFI might give you some issues stepping down to 12V to run it.

GL is selling off hundreds of 24V IP, glow plug and starter equiped 6.2's just about weekly right now. Buy a lot of 3 and you will probably have at least 1 good engine with a good spare if not 3 good ones. It is a gamble. They will also wire right in. Just make the ignition lead go to the IP and you are done. The glow plug circuit will have to be made seperate though.

A 24V pump solenoid for a 4BT can also be found for less than $30.00.

Basically, the wiring is a non issue with an engine swap.

[teking]

Would I be correct in assuming the 24V starter on the truck will not work? Everything in the current truck is in good working order. Its just all stock.

[Barrman]

The stock starter will only come close to maybe possibly almost working in a Ford straight 6 gasoline engine. Maybe, almost possibly in a Ford V8 to, but I doubt it.

Pretty much nothing except the temp and oil psi senders will cross over. You can make mounts for the 24V alternator to fit, but everything else needs to be meant for the engine you put in.

[wrecker]

Just a quick thought, your stock all original truck is going to lose about half its value once you modify it. It is yours and you should build it the way you want though.

[teking]

YEah I've thought about that ... but honestly I have no idea what it's worth.