337 Flatheads...It's an addiction!!!
Someone posted on a previous thread asking about a reply that I made about the 337 motors all seem to be different in some way or another. Not all 337 are the same. Now I've only done a little research and this is by no means an exact factory spec. Its only what I've experienced on motors I actually own and those I've found on line that I've inquired about and the info I was given.
Most references to the differences are about the lifters, Lincolns having hydraulic lifters and trucks having mechanical. But, some truck 337’s also have hydraulic lifters. What or when the change happened, I'll have to do more research. My guess is when they rated the horse power from 152 hp to 155 hp. That also may be when they relieved the block too. I have a truck engine that is relieved around the valves. I read somewhere that they did do this at the factory.
The easiest difference to see is the Lincoln heads and the FoMoCo heads. Again my guess is that early 8EL Lincolns had heads that have Lincoln in scroll writing. Later 8EL Lincolns have heads that say FoMoCo. My two 49 lincoln motors have Lincoln on the heads and the 51 says FoMoCo.
The distributors are different for the trucks depending on a tach drive off the distributor.
Another difference is the crankshaft end where the flywheel mounts and the flywheel itself. Lincoln used a unique vibration dampening (for lack of better word) type flywheel. Its a three layer flywheel with felt between the layers. I'll have to post a picture because its hard to explain.
If anyone else has more to add about the 337 flatheads, please post. I think the trucks are all different depending on the application the truck was going to be used for.







