I'm selling a motor out of 75 ford F100. I was pretty sure it was a 300, but buyer asked how to tell difference? I see vin number has "B" which indicates 300, but motor was rebuilt. might not be original. I see the same casting numbers for both 240and 300. No aluminum tags left on motor. Front of block beneath head has "5J1fF". How do you tell the two motors apart?

Thanks, Bob.

 

check this link out: http://fordsix.com/forum/viewtopic.p...318&highlight=

but a quick way to check is the stroke, a 300s is 3.98" and a 240 is 3.18"...

 

Thanks for reply. I was hoping there would be a way to do it without pulling pan, but checking stroke would definetly be accurate. With same casting #'s etc. maybe that is the only way to check? I will have to join fordsix.com before I can view your link.

Thanks again, Bob.

 

The link just went through. I'll stick something in plug hole. Thanks.

 

The motor had a 4" stroke so it's a 300. Thanks for your information.


Bob.

 

np, glad i could've helped...