360or390
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360or390
good moring people bought this 75 f250 a few weeks ago. the guy said it had a rebuilt 390 in it but the tag on the valve cover says 360 i guess im not sure what the actual difference is between the two besides ones bigger that the other is there anyway to tell a 360 from a 390 thanks guys
Last edited by IB Tim; Mar 18, 2006 at 04:48 PM.
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Joined: May 2005
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From: Graves County, KY
Impossible to tell them apart by looks alone. Only way to be sure is to measure the stroke with a dowel through the spark plug hole. It's possible that he stroked it to 390 during rebuild (very easy to do), but ALOT of 360s miraculously become 390s when the FOR SALE sign goes up.
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From: In the Middle
Originally Posted by bootsman
is there anyway to tell a 360 from a 390
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Cargo Master
Joined: Apr 2001
Posts: 2,364
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From: Eustis FL
You can screw a fitting into a spark plug hole, with a nipple on the other end and some clear tubing. Find BDC of that cylinder, then fill with oil until the tubing is filled too. Then slowly crank the engine until the cylinder is at TDC, and catch the oil in a container that will measure it. Convert to cubic inches, and multiply by 8.
I had what I thought was a 360. Turned out to be an FT block bored 4.13 (Cobra Jet) and a 428 crank (1U cast).
I was happy to find I had a 428 CJ in my ol' 74 F100! The owner before me had a 2V intake put on it lol.
It took me a while of figuring to find out what it's displacement was, and that was the final idea I had to find out for sure.
Mark
I had what I thought was a 360. Turned out to be an FT block bored 4.13 (Cobra Jet) and a 428 crank (1U cast).
I was happy to find I had a 428 CJ in my ol' 74 F100! The owner before me had a 2V intake put on it lol.
It took me a while of figuring to find out what it's displacement was, and that was the final idea I had to find out for sure.
Mark
