I may be able to help out here.As my screen name mentions I am a buick guy.We run a cast ductile iron girdle that incorperates all five main caps and ties them to the pan rails.We have to machine approx .250 off the top of the main caps in order to install it.TA performance sells it for around 500.00 with all related hardware.
We need to step up to one around 650 hp but I know a few guys that have made more with out one.Even with the girdle the main webs end up ripping out of the block.It starts in the main cap bolt holes and travels up the web.Either that or the block splits up the main oil feeds.We have found the failures really start happening when you start spinning the things 7k plus and 800 plus hp .Ultra light parts help but it becomes hard when the only aftermarket crank we have is a moldex billet that weights 80-95 lbs.I haven't heard of one lighter than this.Our highest hp guy out right now is around 1500hp blown alky deal but he goes through atleast one block a year.The girdle does help contain all the junk inside the motor when the block goes.
So do block girdle's help yes but they are not the end all be all to the weak block issue? NO.It's the only thing the buick guys have right now so we make do.If you are going to push it past 800hp save up the coin and buy a IA2 block.I just wish Bulldog would get our block done
