Flathead help needed!!!

[slamchop]

I have a chance to pickup a 4" merc crank.Need help on identifying it before I buy.

[296 V8]

check for 5/8" clean out plugs in the 4" the 3 3/4" has 3/8" plugs most of the time.

[slamchop]

Ok but I need to know about that other times,my gramps said its a 4" crank but it has the 3/8"holes.I know its a later crank because of the 2 oiling holes,is there a way of measuring?or other key things to look for? http://www.jalopyjournal.com/ubbthreads/images/graemlins/confused.gif

[Fastsporty]

I think if I remember right, the counter weights on a 4" measure over 6 inches across and 3-3/4 crank is at or a little less than six. if you need more info than that I can go out into the garage and check some other stuff out. But 286 is probably the x-pert on the weird stuff

[Lionheart]

Some of the Canadian 4" cranks, i've heard, had a 3/8 plug.

[286merc]

Nope, you guys got it covered. As close as I am to Canada Ive never seen a 4" Canadian but have also heard theirs are 3/8" cleanouts.
Ive a few Mercs stored at the shop, I can get exact counterweight measurements if needed.

[29SX276]

In addition to the 3/8" cleanouts in some Canadian cranks, the Merc(4") crank has a thumbnail sized dimple in the front c/w.You can't miss it.

[Jim Marlett]

Measure the length of the big, wide counterweights. Fords will be in the neighborhood of 1/8" less than 6" long and Mercs will be in the neighborhood of 1/8" more than 6" long. It's pretty safe to assume that any thing over 6" is a Merc.