Posted this over in the engine area (i think area 51 as no one has replied )for the flathead. Question Is there anyway to id a flathead other than looking at the crank to tell if it is a Merc? Both heads on my motor say merc on them and as far as I know it came out of a 50 52 F-1 . OK Ross step up to the plate and all other Flathead guru's.

 

No, the only sure way is measuring the crank or measuring the travel of the pistons.

Lots of Merc heads were put on Fords in the mistaken belief it adds power. It actually reduces the compression ratio.

 

I know my flat 8 has One head mercury and other head is a ford. Guess maybe I have best of both worlds??? Anyway I guess the mercury has a dimple on the top of the counter weight which tells it's a mercury.

 

If you have or can take the oil pan off, the Merc crank has a dimple on the front counterweight that the Ford doesn't.

 

You'll have significantly lower compression on the bank with the Merc head, and "normal" compression on the Ford side, if you have a 239 Ford engine. It could cause some vibration but not sure you'd notice.

 

thanks for the info! Vibration hard to tell. The truck feels like it's all vibration while driving it. But I love it just the same. I am going to put some better heads on it down the road.