Who makes full roller rockers for olds 400 with 5/16 head stud and 3/8 stud shaft , heads were put back on engine before rockers were bought so now not going to up size head stud size need to find good quality full roller rockers, cam lift is 523 hydrolic and dont want roller tip type or does anyone have a good combination setup

 

Comp Cams makes an Olds “conversion” stud that is 5/16” base stud for the head and 3/8” upper for the roller rockers. Another idea might be Harland Sharp pedestal rockers, they’re nice pieces. I believe either of these would be sufficient with your cam & springs. Double check spring pressure for compatibility.

 

Can I use a small block ford 3/8 rocker and would crane gold be a good choice of something else

 

AFAIK people certainly have used the Ford rockers and with some manufacturers that is what you are getting. For me, only a dedicated Olds rocker will do thus my mention of the Harland Sharp products. There are people far more knowledgeable than me on the details of this subject, let’s see if they can shed some light for us.

In the interim you might want to try various searches on this site around a theme of “Ford rockers.”

 

You can use the pedestal rockers or the 5/16 to 3/8 studs bccan mentioned. If you use the studs then just call Harland Sharp and they’ll do a set of Olds rockers for you set up for a 3/8” stud.
Either way will work just fine.

 

Keep in mind that with the stud mount rockers you need a pushrod guide plate also. The Harland Sharp pedestal mount do not use guide plates and are direct replacement for the stock Olds equipment; that would be my choice. Either way, the conversion stud and guide plate or the pedestal mount, the 5/16" thread into the cylinder head is the weak point and restricts your safe open valve spring pressure to no more than 350 lbs. With the advertised lift of your cam, 523, the valve springs are most probably well within that number.