Dan, not correct in all cases.
ARP make stainless bolts that are 170 000 psi strength.
Grade 8 is 150 000 psi, and the factory 8.8 european standard studs are likely less than that- probably around 120 000 psi, so the ARP studs I have in my 544 are about 42% stronger than stock. More importantly the alloy used in *very* malleable - the studs can be folded double in a jig & press without breaking. Stainless also tends to be a "sticky" material, so the nuts stay tight more reliably. For early carbed engines p/n 400-2401 (card of 4) works well, for later injection cars p/n 400-0301 (singles) will have to be substituted in certain positions where a longer stud is required. Email me at iadr@hotmail.com if you want some of these studs- they are prety expensive though.

Ian