AcDelco 11' clutch

[Keith B.]

I need a clutch for my 396 and found on the evilbay a AcDelco 11" clutch kit with a GM # 381258. Is this a good clutch.

[Dick W.]

Re: AcDelco 11' clutch

My choice would be LuK. I have had very good results with their clutches. I am thinking that the 396 used the 10.4" clutch, but then again I could be wrong.

[Michael H.]

Re: AcDelco 11' clutch

My choice would be LuK. I have had very good results with their clutches. I am thinking that the 396 used the 10.4" clutch, but then again I could be wrong.

Dick is absolutely correct, as usual. The 65 396 used a 10.4" clutch with the small light weight flywheel.

[Keith B.]

Re: AcDelco 11' clutch

I have a 621 Bell housing and a 11" flywheel

[Joe L.]

Re: AcDelco 11' clutch

I have a 621 Bell housing and a 11" flywheel

Keith-----


That set-up is not original for a 1965 L78. It must have been retrofitted at some point. Incidentally, the GM #3899621 bellhousing did not even exist in 1965.

You require bellhousing GM #3858403 or 3840383. These are long-since GM-discontinued but rather easily obtained in good used form. You also require the 10.4" clutch with 12-3/4" flywheel. You can still purchase the flywheel from GM under GM #14085720. The clutch assembly is no longer available from GM.

The ACDelco clutch assemblies are manufactured by LUK or Sachs and are simply packaged in ACDelco boxes. These will work fine regardless of what box they are supplied in.

Addendum:

I should also have mentioned this: all 1963-68 Corvette small blocks used a 12-3/4" flywheel with 10.4" clutch. The same size clutch and flywheel was also used for 1965 L-78, 67-69 L-88, and 1970-72 ZR-1. However, the small block clutch and flywheel was NOT the same as those used for the L-78, L-88 and ZR-1 applications. Those applications used a special lightweight flywheel (the current successor of which is the GM #14085720) and a heavy duty pressure plate and friction disc.

The current 10.4" clutch available from ACDelco, LUK and Sachs is equivalent to the 63-68 small block clutch. The LUK part number is 04-021. A direct replacement for the heavy duty pressure plate and friction disc originally used for the L-78, L-88 and ZR-1 applications is not, as far as I know, available. However, I think the small block clutch will work ok for normal street operation.

[Keith B.]

Re: AcDelco 11' clutch

I am sorry to add this is for my 66 SS Chevelle. I was thinking it was all the same for all BB

[Joel T.]

Re: AcDelco 11' clutch

Keith-----
That set-up is not original for a 1965 L78. It must have been retrofitted at some point. Incidentally, the GM #3899621 bellhousing did not even exist in 1965.

You require bellhousing GM #3858403 or 3840383. These are long-since GM-discontinued but rather easily obtained in good used form. You also require the 10.4" clutch with 12-3/4" flywheel. You can still purchase the flywheel from GM under GM #14085720. The clutch assembly is no longer available from GM.

The ACDelco clutch assemblies are manufactured by LUK or Sachs and are simply packaged in ACDelco boxes. These will work fine regardless of what box they are supplied in.

Addendum:

I should also have mentioned this: all 1963-68 Corvette small blocks used a 12-3/4" flywheel with 10.4" clutch. The same size clutch and flywheel was also used for 1965 L-78, 67-69 L-88, and 1970-72 ZR-1. However, the small block clutch and flywheel was NOT the same as those used for the L-78, L-88 and ZR-1 applications. Those applications used a special lightweight flywheel (the current successor of which is the GM #14085720) and a heavy duty pressure plate and friction disc.

The current 10.4" clutch available from ACDelco, LUK and Sachs is equivalent to the 63-68 small block clutch. The LUK part number is 04-021. A direct replacement for the heavy duty pressure plate and friction disc originally used for the L-78, L-88 and ZR-1 applications is not, as far as I know, available. However, I think the small block clutch will work ok for normal street operation.

Keith;

You can get the correct fly wheel from KajunJon out of Texas WWW.kajunjon.com for about $135.00 I have one of his in my '65 L78. As far as 403 bell housings go, I have two sitting in my garage.

Good luck,

Joel

[Joe L.]

Re: AcDelco 11' clutch

I am sorry to add this is for my 66 SS Chevelle. I was thinking it was all the same for all BB

Keith-----


1966 Chevelle SS used a 14" flywheel with 11" clutch. However, it did not originally use a GM #3899621 bellhousing. It used a GM #3872444 but the 3872444 and 3899621 are functionally interchangeable.

By the way, the 3872444 was also used on 1966 Corvettes with big block. In fact, 1966 Chevelles with big block are the primary source from which the 3972444 bellhousings for 1966 Corvette restoration originate. That's because there were a LOT more 1966 Chevelle SS396 built than 1966 Corvette with big block.