6.2 Diesel in a M-37?

Ive been kicking around the idea of dropping in a 6.2 GM Diesel into a M-37. Now I know it should be MOPAR whatever it is but I am just wondering if anyone has done this? I love those 6.2 diesels.

That is just weird.

If I was you I would rather drop in a 4bt cummins, you can turbo it and have 10x's the power that 6.2 ever thought of having.

Once I find a 4bt at the right price I will be doing that to my M37

I can see the 4BT appeal. Big power and economical as well as indestructible. I think the 6.2 would make a nice powerplant as well. The 37 is low geared with fairly weak axles and poor brakes. A 6.2 would not just blow the axles away. It would also be nice and smooth as well as economical to run. It would be a simple installation being naturally aspirated. It would be easy to run a four or five speed behind the 6.2.

NO. Definitely go with a 4bt. Much higher quality engine. More power, more efficient, more flexibility, MUCH more reliability.

I know its kind of a "wierd" idea but I have a few 6.2 engines that I would like to do something with. Now I LOVE the 4bt but how much are they?

The 6.2 will be screaming on the highway unless you run bigger tires, put in an overdrive tranny, change the axle ratios, or a combination of these. You may also have steering column clearance issues.

WARWAG said:

I know its kind of a "wierd" idea but I have a few 6.2 engines that I would like to do something with. Now I LOVE the 4bt but how much are they?

Click to expand...

They can be anywhere from cheap ($500 +/-) to super expensive depending on the condition and whether they've just been rebuilt, decked out with a fancy IP and head etc, and things like that. I know around here in the SE you can get them cut out of old panel-vans and delivery trucks, but I'm not sure about your area.

You might want to look at the 4bt-swaps website. Just punch that into Google and it should put you to their forums. I can't remember the link off of the top of my head.

For the cost of one Cummins you could get a handfull of the 6.2's.Undoubtedly the 4bt is the choice but economics could be factor too.

The 6.2 is comfortable running at the Cummins governed rpm, with the ability to turn much higher if needed. You do not want to be running over 2400 all the time, but an occasional run over 3,000 or even 3,600 should not kill the 6.2. I am talking about if you need to pass something or want to get out of traffic. The problem with developing the potential for much speed is that the braking system is not up to par either. I fully agree the Cummins is the better, stronger, longer lived engine. I am a genuine Cummins guy, but I can see where a 6.2 would be a nice alternative for the M37. We have a M37 on a ranch in the southwest part of our county that has not been over 7 miles from home for years, it was purchased from rural fire at least 25 years ago and has been working every year on the ranch, it is their favorite fencing truck. Slow, reliable and easy to work out of. I tried to buy it several times, it is not going anywhere as long as Mr. Johnson is still alive. In his application, a 6.2 would be super. They put 318s and larger Mopars in these pretty regularly, so I doubt that the steering column is a huge issue. Personally, I would rather have a 4BT, but for a song, a 6.2 might be an easy ticket. It is smooth and makes good torque at low rpm.

i saw an M37 with a 3.53 gama goat motor in it ,it was cool !!!!

PM tanner he has donethis aleady, I am still gathering parts to do the same BTW I think there a thread some where about using a column and a box out of Chevy cut away van

you all talk about the brakes might be weak for this swap, there is kits out there for both front/back POWER DISK BRAKES, in fact there was a write up in MV mag. some years ago, also the guy who used to own MV mag. did this converson to his M37, if I remember , he said you could lock the brakes up real quick

The 6.2 & 5-speed swap has been done with good success by a gentleman named Juan and others in the past - I am on-again/off-again on my swap due to work/family obligations. PM me for details, but the basics are that I have a 6.2 with a GM medium-duty (C60) truck bellhousing & a Spicer 3053A Deuce (multi-fuel) 5-speed trans bolted together now, sitting between the M37 frame rails. I was also involved (in a limited capacity) when Cabell Garbee did the Cummins 4BT swap on his M-37. Both trucks are currently at his house.

I went the direction of using the 6.2 for a number of reasons:
- 6.X motors in running condition are cheap -I bought a good running/driving civvy J-code '89 GMC truck for cheap as a parts source - starter crapped out on it...
- they are rated 3400/3600rpm from factory; would I run one at that speed for extended periods? No - it wastes fuel & is well beyond it's HP/TQ peak at those revs.
- The 4BT is awesome, but used market is pushing $2.5-3k for a runner in known good condition, then you get to decide what gearbox/adaptor plate combo to run behind it. NV4500 would be an excellent choice, but $1000+ for a good one & pricy synthetic oil steered me away from this - and NV4500 has some documented weaknesses...
- 6.X parts are dirt-cheap
- Ft Worth Clutch quoted me a mod'd 6.X clutch disc with a Spicer 10-spline hub for @ $100~, so this could be used with a stock 6.X flywheel.
- Motor & trans mounts would have to be fab'd for either a 6.X or 4BT swap; no biggie & I have a reasonable solution/source for this requirement...
- did I mention that I'm a cheap Scotsman?

My chassis still has stock 5.83 gearing, but the high-speed capabilities of the 6.X, coupled with a OD 5-speed & 1100x16 tires should equate to highway speeds; the 4.89 gears would be icing on the cake, but refer to the prior comment about being a Scotsman...

Power steering conversion boxes exist for the truck - old method was to use reverse rotation Dodge truck box; some Chevy vans use same/similar box & the disc brake conversion from Helitool are still available - even upgrading to just front disc brakes would be a big improvement.

But first of all; consider the intended use for the truck...

'Tanner'

If you go with a 6.2, and are using a manual transmission, make sure crankshaft was machined to accept clutch pilot bearing.

Thanks for all of the replies. Ive been shopping around for a 4bt and man the prices are getting STUPID high! I think I will be going with the 6.2. I would LOVE to have a manual transmission. Mr. Tanner I will indeed PM you for details. Do you also have a thread started on your conversion? If anyone has more info on such a conversion please post pics here or a link to your thread.

I installed a 6.2 with the 700R4 OD trans/married Tcase,4.89s,,,, preforms great ! I used the crossmember out of the doner truck and bolted it inbetween the M37 frame with minimal mods, the trans crossmember needs just 4 holes. Had to grind about 1/4 in off top of frame rail on one side and put a notch in the oil pan to clear the diff. I would highly recommend the conversion. It is quite which is a big plus, it has a lot of guts taking off,(you have to be careful not to spin the tires)

A few people in this thread have mentioned inadequate brakes on the M37. In a stock truck, if the brakes are in good condition and adjusted properly, a hard application of the brakes should lock the wheels. If they don't, something is wrong with your truck...

Part of what I love about the M37 is the smooth and quiet original 230 flathead. To me, the truck just wouldn't be the same without it. If I wanted to go faster in something with a 6.2, I'd buy a M1009.
Joe

I was at a stop light and saw an M37 but heard diesel. Followed the guy to parking lot and talked with him. He had put a Detroit 3-53 in it. Fit right in and looked very nice. Said it had tons of power.

The M37 is a 4x4 platform that you can put in basically whatever you feel like. The later M715's were basically the same deal. I put a 6.2 with an NV4500 and followed that with an NP205 in an M715 and it was a decent set up. The 6.2 with the manual tranny definately has a mechanical feel as you're driving and much, much different than the slushbox behind it. Perks the engine up a bit too.