How can i tell what engine is in my 75 dodge rv. I want to take it out and build it for a future project.

All here.

Open Roads Forum - RV.Net

https://www.rv.net > print > true > pging > true > page
I have a 1977 Dodge Journey motorhome with a 440-3 engine. ... Spark Plug Gap and Number: .035" (0.9mm) ... Both 1978 and 1979 show the same plugs.

Question -Spark Plug Gap? - DodgeTalk Forum

https://www.dodgetalk.com > threads > question-spark-...
Feb 7, 2009 - Yeah .035" on pretty much every Dodge engine from 93-back. And could somebody please remind me why the HEI swap is so much better?
Missing: Rv ‎' Must include: Rv

Spark Plug Gap Chart - Brisk USA

https://www.briskusa.com > spark_plug_gap_spark_plug_...
The spark plug gap adjustment should not be changed more than 3 times and should not exceed .008" in either direction. Excessive changing of the spark plug gap ...

1970-75 Dodge Tune-up Specifications

https://www.tpocr.com > dodge2
1970-75 Dodge engine tune-up specifications including timing, dwell angle, and spark plug gap, and firing order.
..

the dodgve parts site will tell you all that,
and if it works and or must be reprogrammed.
The TCM is for the transmission only unless inside the PCM
and many engine there may 2 transmission used even in one production year, for sure before july 1 or after, any year.
why not ask them this,
tell them your cars year and the build codes there.
also some engines have variants, like VVT or turbo or even 3 head types on the engine, build codes tell that too.
ask dodge this, and not blow wad of cash , reading lies on the internet or wild guessing by dweebs.
ask dodges direct. and win,

the Dealer can see your VIN (USA>?) and the serial and pull up build codes. and all that is now known, what to do next.
for sure expensive parts like this./

eBay is the best bet .

6 kW Larger Gas RV Generators

How to Build 454 Chevy Engine

Chevrolet Big Block engine

https://www.summitracing.com/search/Part-Type/Crate-Engines/Make/CHEVROLET/Engine-Size/7-4L-454

454 Budget Build

How much horsepower does 454 engine have

Not 30 or 60#

Those two are not within 10%

Do a Cylinder Leak Down Test

Leak Down tests tell you something about intake,exhaust,rings
& head gasket issues, compression on a good engine isn't
always listed, but no engine runs on 75 #


When you come to a web site provide some details
You don't even have an engine

Engine Wiring ? or Firing Wiring order ?

you need to have the engine coolant switch checked,since the computer relies solely on sensors,the ect tells the computer how cold or hot it is so the computer will make it a rich or lean mixture to start the engine,if it tells the computer that it is 75 degrees the computer will lean the mixture like starting a car in the winter without a choke.

you need to have the engine coolant switch checked,since the computer relies solely on sensors,the ect tells the computer how cold or hot it is so the computer will make it a rich or lean mixture to start the engine,if it tells the computer that it is 75 degrees the computer will lean the mixture like starting a car in the winter without a choke.

have the ECT checked,
Engine coolant temperature,lets the computer know whether it should push more fuel thru for cold mornings ,
the sensor could be telling the computer that your engine temp is 75 degrees,means less fuel being pushed

There is not enough room on this site, suggest you contact Toyota motors USA and ask for the info, u would be surprised how helpful they can be, you may be a future customer.