Kiss_My_99SS

iTrader: (8)

Are these cracks normal? Why are the 2 holes bigger on one and not the other?
drum1
drum2
drum3
drum4

FLT

iTrader: (1)

The holes are different sizes because I believe this is how the balance the drums. As far as the cracks, your pictures are kind of unclear. Sorry They might be just marks from when the drum was casted.

Kiss_My_99SS

iTrader: (8)

I can feels some of the cracks with my finger nail. How can i tell if they are just casting flaws? My old drum does not have any marks like this. Is it common to see marks like these?

FLT

iTrader: (1)

I have seen it in the past. Casting marks at times do look like cracks. I usually will look on the inside of the drum and see if it is a clean break. If you have doubts do not use it. By the way your links do not work.

Kiss_My_99SS

iTrader: (8)

I just fixed the links you should be able to tell more now.
Thanks for your help.

Kiss_My_99SS

iTrader: (8)

The inside of the drum looks fine no marks.

2002_Z28_Six_Speed

iTrader: (19)

I would say that it is not a crack. Looking at pics 3+4 I noticed that the mark in question didn't go into the recessed, machined area and if it was a crack it should be visable there. The depth of the surface imperfection is minute.

Looks like surface imperfection from die casting.

Pic 2 doesn't look like this though sigh

FLT

iTrader: (1)

The links work for me now. It does look like a casting mark to me.

performabuilt

iTrader: (25)

agreed from looking at links they are just casting marks

smoknta

Sand it down slightly and see if they go away. If it is a casting mark, it should sand right away. If it does not go away it is a crack.

PBA

Yes, they look like casting marks, have seen this a few times.