I am going to get a set of roller rockers for my 327 and dont know if I need 3/8 or 7/16 studs. Thanks!!!---

 

With the can type and specs you listed in the other thread you started, 3/8" are PLENTY strong. Typically you wont need a 7/16" stud until you start getting into big lift roller type cams that use high spring pressures and tend to deflect valvtrain components. You application is very simple and "cut and dry" nothing exotic needed until you step up the entire valvetrain.

 

SO the 3/8 will fit with my older valvetrain right? As far as I know the heads are all stock besides the "302" z28 gm springs were added to compensate for the 222/222 .447/.447 114lsa cam I have. The stock stud is 3/8? ---

 

You'll have to tap the threads and depending on heigth may require area stud will bolt into to be cut down as well, otherwise rocker might no even be close to matting with the valve stem.

 

So you say the stock stud is 3/8 that I have already installed , and if I want to go to 7/16 (not even needed for me ) I would have to pull out the old ones and tap for the new ones? Thanks---

 

no,its going to be the stud on top,both the 3/8 and 7/16 will screw in,its the part that sticks out thats thicker.
if your starting from scratch go with 7/16,why not,price the same
if you got 3/8 already stay there,like he said unless your totally radical 3/8 is fine for most street.
your 3/8 rockers wont fit 7/16th studs and vice versa

 

no,its going to be the stud on top,both the 3/8 and 7/16 will screw in,its the part that sticks out thats thicker.
if your starting from scratch go with 7/16,why not,price the same
if you got 3/8 already stay there,like he said unless your totally radical 3/8 is fine for most street.
your 3/8 rockers wont fit 7/16th studs and vice versa

 

Standard SBC rocker studs are 3/8". As mentioned above, a 3/8" rocker for you will be fine. My old 383 stroker used 7/16" stud rockers. To do this with a stock head that has pressed in rocker studs isn't recommended. If you have spring pressures high enough that you need a 7/16" stud, chances are you'll pull it out of the head.

If your heads have been machined for screw in studs, you just need a conversion stud to use 7/16" rockers. The thread hole in the head is still 3/8" so the head doesn't need to be modified. The top part of the conversion stud is 7/16". If your heads still have pressed in studs, they can be removed and the stud boss can be machined down and tapped for screw in studs.

Gen V BBC engines are the same way. From the factory they use a 3/8" stud, non adjustable, valve train. All other BBC engines use 7/16" stud rockers. To convert to 7/16" stud rockers so you can use normal aftermarket parts and convert to an adjustable valve train, you simply buy the conversion studs. Unscrew the factory studs, screw in the conversion stud and install any aftermarket BBC rocker. Normal BBC rocker studs have 7/16" top and bottom but they also see much higher spring pressures than most SBC engines.

If your SBC engine gets over 200 pounds seat pressure on the spring which means about 600 pounds open pressure, you may consider getting the stud holes in the heads retapped for 7/16" and use BBC rocker studs.