When I ordered the studs from Summit, they did not have a 3" long ARP, and the Dorman studs I used are advertised as Grade 8? I even checked their catalog.

These were torqued to 35ft/lbs, do you think I need more pre-load?
ARP shows 45 ft/lbs for 3/8", 180,000 psi bolts?

I did order some ARP studs to replace these.

The heads have already been modified with 3/4" long timesert thread inserts, after milling the stock shafts off and using the Max wedge type rocker stands/hold downs. I'm not sure how I could goto 7/16" with the reduced diameter T&D shafts and have the rockers oil through the rocker shaft?

How much would it cost to have ARP make some custom studs???

FWIW, I ordered these: ARP-AJ3000-5B
Summit has the material listed wrong as 4037?

This is the description from ARP:
Stud, 8740 Chromoly, Black Oxide, 3/8-16 in. Base Thread, 3/8-24 in. Top Thread, 3.0 in. Length, Each

These ARP individual studs are made from 8740 chromoly steel with 190,000 psi tensile strength. They are precision centerless-ground and thread-rolled to Mil-S-8879 specs and have a black oxide finish. A nut and washer are sold separately.