Identify motor, other troubleshooting.

[audioguyinMI]

So, '75 D23 Dodge.

Valve cover leaks, minor exhaust leak, poor gas mileage.  But I dunno whether I have a 413, 440, or what.
It's built on an R40 chassis, but that's not descriptive to the guy on the other side of the parts counter.

So, my questions are these:

1.  Is there a particular truck model which I can use at, say, Advance Auto when all I want is an oil filter?

2.  Is there a VIN decoder that will tell me what my engine/tranny/etc is?  Wait, as I type that, I think I have the service manual, which has a VIN decoder.  I'll go look after I post this - maybe I answer my own question.

3.  Is there a consensus regarding carburetors and exhaust - like, once I figure out what motor I have, these headers work really nicely and this carburetor (a rebuilt stock one, perhaps?) that work particularly well.  Not really into going to the trouble of TBI or other more modern devices.

4.  Are there other mods that increase the reliability - external transmission cooler, etc?

Overall, the thing is really solid, and surprisingly easy to work on.  I just want improve mileage incrementally and get rid of burning smells.


Thanks for any and all input/feedback.
-Bill

[Oz]

Truck model to use for common parts - >  D300 .  When they look it up be sure to select the HD 440 engine size.  440-3.  HOWEVER - I highly suggest you check here on the boards before ordering parts from there.  Especially the thermostat.  There's a "sticky" topic on that at the top of this board. 

VIN Decoder - > Look to your right at the side blocks.

Unless another motor was put in, you would have a 440-3

Increasing gas mileage - > http://www.classicwinnebagos.com/forum/index.php?topic=536.msg536#msg536

and you can enter "Increase gas mileage" in the search and find a lot of info.

Transmission cooler - >  http://www.classicwinnebagos.com/forum/index.php?topic=956.msg966#msg966

[audioguyinMI]

Yes, it's a 440-3.

I also discovered that it's an R400 chassis, not R40. 

Thanks for the link to the mpg thread.

Could it really go from 5MPG to 8 or so?  Who knows how old the carb is - hard to believe it may have seen leaded gasoline.   

[audioguyinMI]

Oh, and I see the VIN decoder now.   

Apparently I was wrong again.  Not R40, Not R400.  R350 (RM300) 1974

Now I gotta go and find out what that means.  It may be that this numerology might include the answer to the first question, i.e.  what's the generic truck/chassis number when I look for oil filters.

Of course, if I simply ask what's the compatible oil filter, someone can probably rattle off a Bosch number, eh?

[Oz]

Sorry, I was doing a quick search for some general topics on your questions while you posted your replies.  Take a look up at my earlier post for just a couple ideas. 

A good thing to do, since we have a lot of info on many topics which most people have, is to use the main part like, carburetor or header or transmission cooler, or gas mileage or cold air intake, and enter that in the search.  You'll be surprised at how much you'll find very quickly.

Yes, 8 mpg is very achievable.  Much of that depends a lot on where you drive and how you drive (given your rig is top tuned condition).  I traveled crossing mountain ranges... 8 mpg would be about impossible there.  But, driving between 55mph and 60 on highway, low, rolling hills, 7 - 8 mpg.  Beyond that... you'll see a lot of debate and variance as to the potential for improvement. 

Of course, if I simply ask what's the compatible oil filter, someone can probably rattle off a Bosch number, eh?

Yup, you're right on the money with that one... oh, and not only the part number, but likely sources and pictures to go with it - LOL!

[audioguyinMI]

Saw the sticky about the thermostat.  Obviously that applies to me, but it generates more questions.

I think it's too hot under than engine cover.  Common sense says the 160 degree thermostat would be the better choice.  I have also since learned that screwing with whatever the manufacturer put in there is likely to cause more problems than it solves.

So the 180 with the special three hole whatever, of the part number listed in that thread, eh?

At least I know I have a 440, so I can go and buy pretty valve covers now.  Right.  Like anyone will see them. 

Time to put a bunch of words in a search box, one at a time.

Thanks much for the help.


-Bill

[Oz]

When you find a topic that covers your questions, if you don't get the specific answer you're looking for, just post your question on that topic.  Chances are, other people may have the same question, it just hasn't been asked yet.   Y!   

Common sense might say to use a 160° thermostat but, the skirted one shown is proven to be the correct one to use or, as you said, it will cause more problems.  It's one of the items for this motor it's best to go with OEM.   

You'll notice that not only does it get hot under the engine cowl, it's also very loud.  When you look at that cover, you'll notice it's just plastic with carpet on it.  Because of this, it does seem very hot; it's like you're sitting under the hood of a truck but, it's not abnormal.  Go with with your temperature gauge on that and, you will find a couple, very good topics here on insulating that engine cover for the heat and noise (Did I just add another item to your search list?)     

A hint on getting chrome valve covers... you can get them cheap enough but, where you live, in about 2 years you'll start to get rust on them pretty badly.  You may want to go with "pretty" NON-chrome ones.

[Froggy1936]

TIP !!  When looking for parts help on vintage vehicles, NAPA is the best And probably the only one with old books. Advance Autozone etc. are all too new an operation to have any info on older veh (they do not even know what a parts book is) they are trained to find things on a computer only if you need a piece of 5/8 heater hose.  You better have a veh name and model for them to find it

[DaveVA78Chieftain]

There is an error in that VIN decode table.  From the Introduction page of the 74-75 Dodge Motorhome Supplement:

The 1973 and 1974 model designations RM300, RM350 and RM400 have been redesignated as M300, M400 and M500 respectively for 1975. Refer to
RM300, RM350 and RM400 illustrations and procedures in the 1973 Motor Home Service Manual (81-370-3073) for information not contained in this Supplement.

So, you have a 74 R4 M400 (RM350).  Because the aftermarket starting out using the RM350 designation in the begining, you can see either RM350 or M400 used as the chassis designation.  When looking for suspension parts (brakes, bearings, tie rod ends, etc.) use only those designations.  This is not a D300 suspension.

Dave

[audioguyinMI]

So, you have a 74 R4 M400 (RM350).  Because the aftermarket starting out using the RM350 designation in the beginning, you can see either RM350 or M400 used as the chassis designation.  When looking for suspension parts (brakes, bearings, tie rod ends, etc.) use only those designations.  This is not a D300 suspension.

That makes sense.  And when so little in today's world does, it's especially nice.  Thanks much. 


We probably ought to fix the decoder table too at some point.  I'd volunteer but it sounds like someone who knows the actual numbers ought to do it.  Thanks again.  And surprisingly, the Advance auto computer has no problem at all with the M350/400 designations.  They continue to improve on older stuff.

[audioguyinMI]

TIP !!  When looking for parts help on vintage vehicles, NAPA is the best And probably the only one with old books. Advance Autozone etc. are all too new an operation to have any info on older veh (they do not even know what a parts book is) they are trained to find things on a computer only if you need a piece of 5/8 heater hose.  You better have a veh name and model for them to find it

Funny you should mention that - hoses are one thing in particular that I find those stores particularly BAD at stocking/identifying.  All sorts of wall thickness issues and ID mismatches (where the printing says it's a 5/8" hose, but it's not)  For many many parts (including finding a used oil pan for my 2000 Grand Cherokee for $65 out the door) my local Advance has treated me very well with lots of knowledge and assistance.  In contrast, the local NAPA store has gone from the best with an attached 10k ft warehouse to a store that's maybe 400 sq ft with a 1000 ft warehouse.  The cats behind the counter are polite and well intentioned, but lacking in knowledge and experience.  I know, right?   

[Oz]

Thank you for pointing out that the suspension parts wouldn't be compatible, Dave.  However, when I went to the NAPA for some common engine parts, that's what they indexed them under.  It was a tip from Slantsixness and I think Im-still-Lefty from way back..  Only the engine though.  (possibly the transmission?)

We probably ought to fix the decoder table too at some point.

Definitely a good idea.  I just tagged that onto Dave's "to-do" list -  D:oH!