I called ARP today and inquired if they carried Head Studs for the N* to my surprise the rep I spoke to new exactly what I was looking for.
He said they have a Kit but it's not labeled for the northstar but for a VW 16 valve DOHC and the part number is: 204-4204 and you will need to of these kits.
He also mentioned that he has been selling these kits to Cadillac dealers for several years. Hmmmm interesting.
The kit has 10 studs, molylube & 10 twelve point nuts. I looked into the specs of these units and they have the M11 x 1.5mm thread and are 6.5" long (165mm) for the block side.(Stock bolts for mine are listed at 152mm) Didn't get the specs for the nut side thread, Sorry.
These babies are rated for 190,000 PSI tensile strength. WOW! ARP mentioned Timeserts were a necessity.
Thought it would be nice to let people know there's a stronger option out there. Especially if your using NOS. They range in price when I searched the web from $104 to $139 per kit.
Not sure if they will work with the newer N*s I thought I read somewhere they have 2 different length head bolts.