Correct flywheel bolts

[Bill W.]

My 65 BB Had a heavy flywheel with two different length flywheel bolts holding it on . I went downstairs to my parts dungeon and had three different lengths of flywheel bolts . A 15/16,13/16 and a 11/16 thread length .I bought a new GM lightweight flywheel , what is the correct thread length bolt for a light weight ?

[Gene M.]

Re: Correct flywheel bolts

Bill,
I don't know the answer to your question, But I can tell you the bolt should stick thru about 2 threads on the other side of the crank flange when tight.

[Joe L.]

Re: Correct flywheel bolts

My 65 BB Had a heavy flywheel with two different length flywheel bolts holding it on . I went downstairs to my parts dungeon and had three different lengths of flywheel bolts . A 15/16,13/16 and a 11/16 thread length .I bought a new GM lightweight flywheel , what is the correct thread length bolt for a light weight ?

Bill------


I recommend using NEW flywheel bolts. The GM part number for ALL Corvette manual trans flywheel bolts is GM #839756. GM says this bolt is 7/16-20 X 1". However, the actual bolts might measure + or - 1/16". They do have an unthreaded shank below the bolt head and this is important.

While new GM bolts are very adequate, I use only ARP flywheel bolts. These are ultra high quality and that's what I want for bolts like this.

[John H.]

Re: Correct flywheel bolts

I've always used ARP flywheel bolts also; note that they are a thread or two longer than the GM bolts and may require a slight "adjustment" of the sheet metal inspection cover to avoid contact.