Help with Clutch Question

[BlueovalFE]

My clutch on the '69 is getting pretty weak. My question is, since I am building a 390 to replace the 360, wouldn't it make sense to resurface the flywheel and use the new parts (clutch, to bearing, pressure plate) on the new motor? I understand a 428 has a different flywheel, so my question is, I guess, can I use all the stuff I buy on the new motor when it's done?

[BlueovalFE]

I found out that the 390 has a bigger flywheel and clutch than the 360. So now, my question is, can I run the 390 flywheel and clutch assembly on the 360?

[390Nut]

Yes, with very little issues. The only real concern is that when building the engine, you have the flywheel with the crankshaft, rods, and the pistons so it can all be balanced properly. Oh, and the flywheels are the same size, they are just drilled with different bolt patterns for the two different sized pressure plates.

The 11" clutch from the 360 is plenty strong with todays materials, as long as you get a good quality clutch (LUK brand comes to mind).

[BlueovalFE]

Thanks for the reply Paul, but it kind of flies in the face of what I found on another site. Here is what it pointed out:


Several weeks and a 1000 posts ago I typed the FE flywheel part numbers and what the difference is. Basically it's this: 352/360's use an 11 inch clutch, 390's use an 11 1/2 inch clutch. The bolt circle is larger for a 390, as you can see:

C5AZ-6375-K .. Flywheel-352/360 ~ 12 3/8" bolt circle

C5AZ-6375-L .. Flywheel-390 ~ 12 7/8" bolt circle

I went to LUK's website today and it was down. Maybe later it will be back up.

[willowbilly3]

While the bigger is better I would aslso agree that the 11 inch clutch would be fine for all but the most extreme use. I would also reccomend a flywheel shim to make up for the amount machine off the original thickness of the flywheel. Otherwise you may find yourself building a longer clutch adjusting rod to get it adjusted out.

[BlueovalFE]

I've about decided to go with a new flywheel instead of resurfacing this one. After all, it's damn near 40 years old and the new ones aren't that expensive.

[willowbilly3]

[Faltura]

On the 360 fly wheel topic, I am thinking about replacing my 360 that is coupled with a C-6 with a 390. Will I have to replace the flyweel as well?

[fordman]

if you are going from a 360 auto to a 360 manual trans then yes you will need a flywheel to replace the automtics flexplate.