Assistance Needed, Heavy-Duty Dodge 360 Owners?!?

[Clueless Boomer]

Can any owners of vehicles with Dodge 360 engines help me out here? I’m trying to figure out which engine/head casting #’s identify the heavy duty version of the Dodge LA 360, the 360-3. It’s the version for truck & RV (and I assume, military) use. If anyone can post the block casting # from their 360-3, it would be very helpful. (It’s located on the driver’s side above the starter, in this form: 4006830-360-2.) The best I’ve been able to do is narrow it down to 2 or 3 #’s by clicking the link to a guide from mymopar.com. Their Engine/Head Numbers Guide 1942-2000, shows 5 engine casting #’s in the V8 Trucks & Industrial section located near the back. It shows that 3 were designated for gasoline-powered trucks and vans from years 1989-1975. However, it does not specify which #’s apply to the 360-2, and which apply to the 360-3 version.

I’ve found there are several ways to differentiate versions of the 360 engines, including:
• VIN # (5[SUP]th[/SUP] digit = K on 360-3 version)
• oil sump location in the pan (van=front, car=center, truck=rear)
• 2 bbl vs. 4 bbl carburetor (360-3 has 2 bbl)
• presence or absence of A.I.R. (smog) in heads (360-3 has none??)
• EGR valve (360-3 has one)
• spark plug thread diameters––14mm vs. 18mm dia.on 360-3

Why am I making a big deal over this? I'm trying to figure out if an engine I'm buying is an LA 360-3 heavy-duty engine or not. It came from a 1978 RV, its block casting # is 4006830, & it has a rear sump oil pan. I don't know its head casting # yet or spark plug size (it's in a yard halfway across the country.) Its heads match a photo from page 23 of that guide showing the 1990-75, 360 Dodge W/A.I.R. head. But these post-smog heads are mounted on what should be a pre-smog engine. (Was original motor replaced?) Any idea what I've got, or which block/head casting numbers conclusively identify the heavy-service 360-3 engine? Your help would be much appreciated, since I want to be certain the engine I'm investing in rebuilding is the correct one to upgrade the (deceased) 318 in my 1973 Winnebago. My apologies for dragging a civilian question into your military forum, but your members are the most knowledgeable I've found on the 318 to 360 engine swap and a slew of other topics of interest for my project. You’ll have my sincere thanks for any assistance your Dodge boys can offer.
Clueless Boomer

 

[randini]

I have a 1977 RV with a 360 engine. It has the AIR heads, without a catolytic muffler. The air pump seized and I just removed it. This was a time when you would find all kinds of odd combinations i.e. Air heads on pre-smog engines. The Air heads where designed to add outside air to mix with exhaust, to improve the burn-off in the catolytic muffler.

 

[NDT]

Consider a 6bt swap. Your Winnie will get maybe 6 mpg, thats 50 cents a mile. You wont want to drive it anywhere. Thats the fate of my M880.

 

[Clueless Boomer]

Thanks for the reply, randini. Interesting to know my engine & heads aren't the only strange mashup out there. Would you be able to check if the 5th digit in your VIN # is a "K"? That K would make it a 360-3 engine. Then I know it might involve some gymnastics, but if you'd be able to check that engine casting # (driver's side, above the starter) that would help me know if the engine I've got is the right one to rebuild. Thanks for your feedback!
Clueless Boomer

 

[randini]

Hi Clueless! at this point in time, I plan to check the the Block Numbers. Lets see if I remember when I get home. ...LOL

 

[Clueless Boomer]

Hey, randini––that would be a huge help! I'm coming down to the wire to the point I need to pull the trigger, probably tomorrow. I hear that the 360-3 block is a chrome alloy premium casting that can stand up to the heat of a constant load better. I hope your casting # will point the way to which # is the right core to rebuild with. If you could check your VIN at the same time, that would about cinch it. Thanks for the help!
Clueless Boomer

 

[Clueless Boomer]

Hey, randini––another RV'er was able to access his block casting number yesterday, a '76 Travco with a 360-3. His VIN # 5th digit was not a "K"––that must be the VIN code for Dodge trucks, not independent RV's built on the Dodge chassis? Anyhow, for your & others' info, his block casting # matched the one on the engine I bought––4006830-360-7. And a dealer subsequently confirmed that # as a 360-3 through the Specifying Dept. at Mopar Direct Connect Technical Line. So it's official, and you're relieved of duty crawling around in your motorhome's doghouse. Good luck keeping your 360-3 humming...I'll vouch that its much easier than trying to track one down across the country.
Clueless Boomer, signing off.