Got me a set of AFR195cc heads and a nice cam with about 550 max lift ive got people telling me to get 3/8 base and 7/16 rocker nut thread size for extra security and strenght do i need this will this help alot ?

 

If I'm reading that correctly, you want to use a 7/16" rocker nut on a 3/8" stud?

 

ehh what i mean is the base of the stud that threads into the head is 3/8 the top of the stud where the roller rocker gets put is 7/16 thus requiring 7/16 roller rockers instead of the normal 3/8 , another question I had is does this change anything going to 7/16 for instance will I need longer push rods different shims ect ??

 

I see. Unless you're doing a monster build up,(like a mechanical roller cam with aggressive valve lift and duration, with some really heavy springs to match.) you don't really need the bigger top stud. the 3/8" will work just fine. It's already gained a lot of strength due to the thread-in seats. If you go that, you may as well have the heads machined for 7/16" base thread as well. You're only as strong as your weakest point.

 

IIRC, the lower thread (that goes into the head) is the same for either 3/8 or 7/16 studs. Its just the top of the stud, where the rocker goes, that is larger. 7/16 would be stronger than 3/8, but what are the specs of the cam and valve springs you are running? I know a few guys using cams much bigger than .550 with only 3/8 studs and no problems.

 

k last thing im unclear on is if I get the 7/16 studs do I have to change anything else besides getting the 7/16 roller rockers ?

 

My old 383 had 7/16" studs. The cam was around .550 lift. Spinning the engine to 7000 rpm, I wanted to make sure the rocker stud wasn't flexing. I also used 3/8" pushrods and guideplates.

You need to buy SBC rockers for the 7/16" stud. BBC rockers, which use 7/16" studs, are the wrong length.

For most applications, a 3/8" stud will do fine. 3/8" rockers are easier to find.