Cast iron exhaust donut?

[Terry F.]

When I took my 68 bb apart I noticed that there were only castiron donuts inside the exhaust flange, no sleeve. Is anyone familiar with this. I am assuming it is original for my car. One of mine is cracked, is there a source for them? Thanks, Terry

[Clem Z.]

Re: Cast iron exhaust donut?

some are made from pressed powered metal that may look like castiron

[Joe L.]

Re: Cast iron exhaust donut?

Terry-----

I've never seen a cast iron exhaust packing (donut). However, I have seen the sintered iron variety which may be what you're talking about. These are not original to your car. Primarily, these were used for truck applications but I use them for cars. Other folks do, too.

I only recommend using these with the extensions just as used with the soft packing. The part numbers are as follows:

2"= GM #3731062

2-1/2"= GM #3768711

Both of the above are still available from your GM dealer.

[Terry F.]

Re: Cast iron exhaust donut?

Thanks for the responces. What I found was two castiron looking donuts and no steel sleeve inserts. I was confused because I seem to recall my assembly manual not showing anything like it. I didn't want to discard them because I met someone with another 68 that found the same thing. Thanks, Terry

[Terry M.]

Re: Cast iron exhaust donut?

I believe the original seals for your car were the fiber style, with the sleeve inserts.

[Clem Z.]

Re: Cast iron exhaust donut?

with the metal donuts they are strong enought that you do not need the sleeves. the general found a another way to save money.

[Terry F.]

Re: Cast iron exhaust donut?

Thanks for the responces. I will put the sleeves back in and the fiber type donuts. Thanks, Terry

[Patrick H.]

Re: Cast iron exhaust donut?

I use the sleeves as well as the sintered metal donuts. I've replaced too many crappy fiber donuts in my 11 years of Corvette ownership to put up with those anymore.

Just my $0.02

Patrick

[Mike McKown]

See your FoMoCo Dealer 460 engine. *NM*