Meplat, I stated in my long post (makes it easy to miss things) that gas-checks aren't recommended in the brake & I don't want to drive lead that fast without them. Otherwise they would be high on my list.
Thanks though.

Dan, i tried once with no luck but will try again. If still no luck, I'll pass them on.

Bob, thanks for he heads up. I have obviously heard of Mark & will try & get ahold of the book. I have heard of it, but where can it be bought?