Flywheel question -

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post #1 of 7 Old 12-04-2002, 12:27 AM Thread Starter
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Flywheel question

A friend of mine found a junkyard nearby with several older wagoneers and cherokees....a couple of them having low mileage AMC 360's. I own a CJ5 with a 304 mated to a T-176 tranny. My question is....if I were to swap out the 304 with the 360....can I use the flywheel from the 304? Does the 360 have the same stroke as the 304....with a bigger bore? My theory is....if use the flywheel and harmonic balancer from the 304....then I should be alright....everything should remain balanced out. Any information is greatly appreciated. Thanks!

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post #2 of 7 Old 12-04-2002, 09:13 AM
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Nope. The 304 and 360 are externally balanced and must use their own flywheel. So you need to pickup a 360 flywheel or you're gonna feel a bad vibe from the motor. I think 4WD has 360 flywheels for $139 plus shipping.

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post #3 of 7 Old 12-04-2002, 09:45 AM
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I have gone through the exact same question with my CJ5 304/360 swap. After talking to what seems like dozens of people I can tell you that there is no concensus. Some "guaranteed" that both flywheels are identical, while others swore that they are different. The 304 flywheel WILL definitely physically fit on the 360. However, according to the people who seemed to have had the most actual experience with this engine swap, I decided to go with an actual 360 flywheel. The engines are supposedly externally balanced, so it makes sense to me that there is a difference in flywheels. Considering the relatively small amount of money involved to chang flywheels, I figured better safe than sorry. Comparing the two, they ARE very similar, but the balancing holes are somewhat different. Replacement 360 flywheels are available from or for about $140. 4WD also has steel billet flywheels for about $250, but I don't know what the advantage is to these. I've also seen them come up on ebay (just don't bid too high!).
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post #4 of 7 Old 12-04-2002, 09:59 AM
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I found a 400 gram balance difference between my 304 and 360 flywheels - pretty significant, I'd say.
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post #5 of 7 Old 12-04-2002, 01:46 PM Thread Starter
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Thanks for all the replies. If I do the swap....I'll buy a new flywheel. No sense chancing it. I was just curious.

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post #6 of 7 Old 12-04-2002, 07:56 PM
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Yes they are different. I have 304, 360, and 401 flywheels and flexplates and all have different weights on them.
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post #7 of 7 Old 12-05-2002, 07:35 AM
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I am going thur the exact same thing........My 304 flywheel was in perfect shape so my machine shop (which does engine balancing)took the automatic flex plate (from the 360) and found the balance on it, then rebalanced my 304 flywheel to it.
Cost $40-50............Have not had it running yet, so can't tell you for sure, but I've used this shop for 30 years and trust them...

1979 CJ7 (YJ tub) full cage, Currie 9inch rear with Warn full float kit, detroit locker, 456 gears both ends, Lockrite in front, T 18 trans, 360, 040 over, Isky cam, 2 into 1 Flowmaster exhaust

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