https://youtu.be/OOCUc_HFmZs?si=8BbBZ29B3ss5U3Aq

What's the difference between a 230 400 block and a motor home block?

Well, there is such a thing as a "motorhome" block. It means it came in a motorhome. But I don't guess it's any better than a regular block. It is made from the same casting. It is described in the Mopar B/RB handbook. It has 2 "steam holes" in the deck under each exhaust port similar to a 426 Hemi. This is why those 2 holes are there when you buy a head gasket for a wedge. (Look at your wedge head gasket.) But that doesn't mean that all motorhomes had a "motorhome block". Don't confuse this with the Very Heavy Main Web 230 block that was made up until approximately 10-10-71. Which is what you should use to build a 1000 horsepower wedge if you are not using an aftermarket block.

No such thing as a motorhome block but I'm not going to bash those guys too hard since they are running a lot of my parts on that engine!
Chrysler just produced blocks. Some went into cars, some into police cars, some into trucks, some into motorhomes. The same exact castings got used everywhere. Some got stamped HP, some got stamped T, etc.

Mopar did not use any 400 motors in any motorhome chassis that I know of or have heard of: up:

Well, I disagree. There is a 440 block that went specifically into SOME motor homes. Mostly the later ones. I’ve got one at the shop. I, unknowingly, bought it new as a short block when Mopar was selling things cheap in the 80’s. It is just machined differently with the ,as mentioned above, steam holes. Ironically, it does not have the heads listed as “ motorhome “ with the special casting number. Those are 213 if I remember correctly. These blocks are matted from the factory with a specifically machined 452 casting. It has the same “steam holes” . Many a motor home has gotten hot before all head gaskets started being produced with those holes. It was not known to get those spec gaskets for a motor home application. These 452 heads also had the smaller tapered seat spark plugs. I can personally testify that my 3/4 ton truck with that block and a set of 906 heads would run very hot on a summer day. My buddy had the same block and head combo that did the same thing. I ended up pulling mine out . He just re-blocked his car to solve his problem. Now the last time this conversation came up( and it seems to do that a lot), some old tech on here said there was a special water pump housing and thermostat that went with that combo and most people did not know that. I don’t know about that but I would not be surprised. Down here in the Texas heat, we were always hearing of some guy burning up his 440 motor home engine.

Now, I’ve never heard of a “400” motor home block.

Thanks fellas ....I read on some interesting facts on 440 sourse.com.

I don't think they put 400 blocks in motor homes. 440 is what i know they used and some could be found with forged cranks and 6 pac rods as Chrysler used up their stock. A friend of mine aquired one and found the good parts inside. I guess Chrysler did not let anything go to waste.

I have seen 413 industrial motors in Class A motorhomes and other applications like generator power plants ,marine and H.D. (5 ton+) trucks.
Those blocks have a bunch of extra reinforcing ribs on the lower sides between the oil pan rails and the bottom of the cylinder walls

The only block that I've personally seen which I couldn't explain was a 426 Wedge block with cross bolted mains. I was told it was for NASCAR applications. I didn't have a camera with me when I saw it (before cell phones were invented) so I didn't get a picture. Guy who was selling Mopar stuff out of his garage had the block sitting in a corner. It was a wedge block but had a Hemi bottom end. Wish I had some pictures of it. There is no record of Mopar ever producing a block like that so it must have been "back channel" or something?

Yes, NASCAR block, circa 1971-72. They were just discussed on here a couple months ago.

The 400 block I am running is "supposedly" a "motorhome" block....1977 date.

When I bought it off the guy he told me that is what it came out of. Can't imagine any reason he would have made that up. It also has the oil dipstick hole plugged and it looks like the factory done it, so I assume it had some other dipstick setup on it which would also lean towards a motorhome. Or even a van chassis?

And its held up pretty well considering what I have put it through.

Do that block have any factory markings like the old HP's/230/430 blocks?

I was told the same thing about the block I used for my 451 and I never questioned where it really came from. After about 15yrs of service and abuse, we named it "King Winnebego Block".

It would probably help to define "Motorhome".

A Class A Winnibago type apparently would be 413 or 440 only.

A Class C, B Van style was probably available with a 400.

Kevin

Not that I recall no. I will have to compare it to my other 400 block when I get the chance. Car is in the trailer right now.

Here is a pic of the dipstick plug.

Dipstick plug just means the block was used in application with a truck oil pan. The truck oil pan has a dipstick tube that screws into the pan.

[quote=AndyF]Dipstick plug just means the block was used in application with a truck oil pan. The truck oil pan has a dipstick tube that screws into the pan. [/quote) Exactly
I'm thinking that some of the van chassis that came with BB in them used that oil pan also

Yes, they do. I have several big blocks that I have parted out of Vans or motorhomes over the years.

230 block...motor home block...HP block...all terms used to get more green from buyers. Loved my 400 motors tho, both were strong runners.