So recently I decoded the vin on my 55 F-100 and started to make a list of the projects I wanted to complete once the new year and better weather came in the midwest. I want to keep more of a stock appearance with the truck and not go overboard on aftermarket stuff.
The vin goes as follows - F10V5P... so using the F100 central website I found out it was originally a 239, built in the twin cities. I was unable to decode farther on the transmission and gears as the other tag in the glove box is long gone im guessing.
The truck now has the 223 6 cylinder in it with a T98 4-speed transmission, 6 volt wiring. I know the truck was orginally a manual as the pedal and hole in the floor look original so could this be the original transmission? I cant find any information on the transmission the 239 came with besides being 3 or 4 speed.
I am also debating returning the truck to original by finding a 239 and rebuilding it. Is this worth the troubles as I read the following on several websites:
It is known for having oiling problems in the rocker shafts due to the fact the oil first went to the crankshaft bearing, then to the camshaft bearings, then to the rocker shafts. This problem plagued the entire Y-block family and could be remedied by running a copper line from the oil pump and then to the rocker shafts.
having lost 2 good running y block motors to the stupid kit that used to be available to cure poor oiling to the rocker arms using copper lines i would stay far away from that idea! the problem being copper lines break and all your oil is on the ground before you know it. the biggest problem was the non detergent oil of the day that did not keep the passages clean.a y block using modern oil and regular oil changes should last a long time if taken care of. the old non detergent oil let sludge build up like crazy.
If you want to keep the truck original, I would find a 239 Y-Block and rebuild it if needed.
I had my 55 239 overhauled by a shop. Could have done it myself , but, didn't want to mess with it while doing the truck.
These year Y-Blocks have a reputation for the rear main seals leaking oil, which mine does even though new. Not a big leak, just a couple tablespoons every time I park it.
Otherwise have had no problems with it since done 6 yrs. ago.
What I would do is find a 272, bore it to 292. 272s are all over the place and cheap. Pistons can be purchased NOS standard size from carpenter for 100 bucks. They sound awesome and have plenty of power.
If you could find a 239 that required no machine work, freshen only, it could be a viable option. Once you start machine work, add parts to rebuild and the costs skyrocket. The Y block is not an inexpensive engine to rebuild. Like said above, go with a larger platform to start. Not mentioned here but very few parts are interchangeable between 239 and larger.