Today I talked to the man who owned my 59 motorhome conversion before the guy I bought it from had it. He said he had a 261 installed in it and it was in it when he sold it. When I got home I tried to see if the engine in it now is a 261. I have checked my shop manual and ran a search on this page but am still unable to verify.
My shop manual shows the location of the engine source, production date and type code stamped near the dipstick but I can find no place to interpret this. It appears to be S0403XXM (the stamps are weak and some charactors are not full).
The inliners website lists 7 digit casting numbers but I can't find one on the block. It appears to have some numbers near the starter but they are caked with dirt. Is that where I should look?
In the archives of this site I read about the 261 having 1/2" pipe thread ports for the oil filter lines. Mine appears to have 3/8" pipe threads at the outlet and 1/2" at the return.
Can anyone clear the air for me?
