anybody running indys or stage 6 in a duster ?

Those are not Champans , and from the look of that picture they use stock valve lengths . You need to compare the roof of the unported intake ports to the ported and make sure whomever ported that didn't make the roof too thin.

Also you need to notch the spring pockets so the oil can escape , as they are not they will fill up over the top of the valve guide and leak into the ports .