Flathead Six models
 

I'm just curious what models the flathead six came from the factory in. I spotted a 1.5 ton on ebay with a six and was just curious if the little 223? was in it or if it would have the 254. Just doesn't seem that the smaller would be in a truck that size.

According to the shop manual - I'll look for more info in my operator's manual - the 254 was only used in the F6 conventional and cab-over.

F6 was rated as a two ton. 1 1/2 ton would have been an F5, so it should have been a 226.

Ok thanks.

There are cast numbers on the head, and also on the block at the pan rail just below and behind the generator. If it says something like 7HA, or OHA it's a 226 cubic inch Flathead. If it's the 254 the numbers will be 8mth on both the head and block. I searched for 3 years to find the elusive 254. I finally found one, and upon tearing it down I discovered it had a broken piston and had put a hole through the cylinder. So maybe I can recoup my investment selling the internal parts.