3/8 or 7/16?

what about 350's .....same?

also are they pressed in ?

Thanks

 

3/8".

Same.

Factory are pressed unless aluminum (or BBC).

 

When I pull the heads off to put new head gaskets on and springs and rollers and all that .... do I need to pull thoes or can they stay ??

Thanks for the info

 

The issue is stress. The load comes from the cam pushing the valve open and the valve spring resisting that. If you keep the valve lift down, you can stay with the press-in studs; but, if you increase the lift, you need to increase the spring force to keep the lifter on the cam because the RPMs are going to go up, too, and the more a spring is compressed (higher lift), the higher the force it puts back on that stud.

If you'll have the heads off anyway, doing the screw-in studs now does tend to make sense.

 

I do want to do because I might be putting a cam in at the same time while I have it all apart...I might as well

How would I go about doing this if I had all the right tools?

how do I know what Threaded studs (size and stregth) to go back with ?

Thanks again for all the good info.

 

pull the studs, a stack of washers anda nut tightened will pull the studs. mill of .4 from the stud boss, tap for the stud and screw them in, use guide plate if needed. i use arp studs and the way they're made a guide plate makes it wasier for the studs to seat so if i have SA rockers i hog out the slot on cheap guide plates and use them instead of trying to counter sink and knock out a couple of threads to make the ARP studs work without them.