360/390

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Feb 12, 2016 | 10:34 AM

Vinford

Thread Starter

Cargo Master

Joined: Aug 2004

Posts: 3,455

Likes: 8

From: Williams Lake B.C.

360/390

Is there any visual way to tell the difference between a 360 and a 390?"

Feb 12, 2016 | 11:30 AM

Gembone

Logistics Pro

Joined: Nov 2012

Posts: 4,308

Likes: 19

From: Las Vegas, NV

No, you have to measure the stroke.

Feb 12, 2016 | 01:29 PM

crazed87bronco

Logistics Pro

Joined: Nov 2003

Posts: 4,371

Likes: 7

From: PA

Nope no way to tell them apart by looking at them. You will need to measure the stroke 3.50" is a 360 3.75" stroke is a 390

Feb 12, 2016 | 01:36 PM

HIO Silver

Fleet Owner

Joined: Dec 2009

Posts: 20,678

Likes: 83

From: NorCal

... And here is how to measure: https://www.ford-trucks.com/forums/7...ml#post6830607

.. And here is one with pictures! https://www.ford-trucks.com/forums/9...l#post13616693

Feb 12, 2016 | 05:10 PM

jowilker

Fleet Owner

Joined: Jun 1999

Posts: 24,552

Likes: 74

From: Creedmoor, North Carolina

I have done it with the wooden dowel, and the white jacket wire from a 12-3 section of house wire. Both will work, the wire is smaller and easier to work with. IMHO

John

Feb 13, 2016 | 02:41 AM

JEFFFAFA

Hotshot

Joined: Mar 2013

Posts: 14,255

Likes: 199

From: Phoenix, Az.

Not from the outside with it still in the truck. If it's already removed you can pull the oil pan and tell by the shape of the crankshaft's counterweights. Between a 360 and 390, the 360's counterweights are squared off. Flat on the outer ends. The 390's are tapered.

Feb 13, 2016 | 03:08 AM

bert cook

Senior User

Joined: Jul 2011

Posts: 173

Likes: 1

From: forks

i thought if you looked at the back of the crankshaft phlange one was round and one had a half moon notch cut in to it

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Feb 13, 2016 | 09:58 AM

KsHighboy

Senior User

Joined: Apr 2006

Posts: 323

Likes: 1

Quote:

Originally Posted by bert cook

i thought if you looked at the back of the crankshaft phlange one was round and one had a half moon notch cut in to it

On the rear flange of the crank there will be a square notch or a half moon and also both on the same crank. All the 390s Ive seen have just had the square notch. Ive seen 360s with just a half moon and Ive seen them that have both a notch and a half moon. Not sure if that is a guaranteed way to tell but that has been my experience.