Just for the sole reason that on their website they show a stock block cracked in half and under the caption they say "Picture above was a FORD Motorsport "A4 Block" I think they are snake oil salesmen and their product is a joke. I think the intake puts plenty of clamping force in the lifter valley area and the cracking starts in the main webbing area not the lifter valley. I don't have either on my motor and it's makine 600 at the flywheel. Theres a thread on turbomustangs.com you might have seen it Scott, it was about Tommy's car that's making like 680 rwhp with just the DSS girdle. I guess it's just luck because some block castings are slightly stronger than others, some people split their blocks at 400 rwhp and others make 650 rwhp and it works fine. I'm gonna get the prc halo type main girdle that ties into the oil pan webbing like the one BarryD is using, hopefully I'll be able to make 600-650 rwhp without a failure. Or should I say, I hope I get lucky and have one of those special blocks.

Briane