I went through the 50s and 60s engines pulling studs with stock springs drilling pinning the studs to try and make the crap work. plenty of people with dead stock low rpm 348 chevys were pulling studs, this kind of stuff is why general motors is now bankrupt just half a-s do something don't do it the right way. It would not have cost gm any more money to do another machining step install screw in studs in the vortec head. If vortec heads were not pulling any studs scoggin dicky would not have bothered to use screw in studs in there upgrade.

Why would a screw in stud break at a very low 6700 rpm anything that turns that low has no valve spring pressure. So far I have never had a screw in stud break, must be some chinese quality stuff out there.

 

Not sure how to respond to this. We're talking today, and I'm not seeing or hearing about GMPP stock Vortecs pulling studs unless there's some insane cam use or brutal RPM. SDPC upgrades the studs only when they upgrade the springs, which makes perfect sense to me. There are a TON of Vortec head builds going on, and they're just not showing this problem from everything I'm doing and reading about.

Different experiences, all good. 'nuff said

 

What I have been trying to say and did say in an earlier post with higher spring pressures that high lift hydraulic rollers require even with the reasonable duration that all hydraulic cams have, all of them without exoctic $1600.00 worth of titanium valves like used in the LS7 to get the rpm up or other expensive tricks they all turn fairly low revs but the lift is up there, one of the other advantages to the roller in the first place, hydraulic roller springs need to be stiffer just to help out with the better lift they have over a flat tappit hydraulic, they are stiff enough they put the pressed in studs in real trouble, this is something that if you put the standard vortec heads on with your flat tappit decide to upgrade your out more money with the vortec heads modifying them when gm could have done it for you, every other head that I know of has screw in studs problem automaticly solved.

Of course no one in this day and age would even try to run high rpm solid cams of any form with pressed in studs.

This is why the scoggin dickey upgraded heads have the screw in studs there upgrading is very expensive. this is why the moddest 180 runner bowtie vortec head comes with screw in studs, no one is going to use a 180 runner for even a 350 if there intention is to keep it high in revs all the time on a race track. the 180 bowtie vortec has the screw in studs for the person that wants a hydraulic roller without it pulling studs.

A pressed in stud if the valve spring prsessure is to high at full lift
is going to work its way out its just a matter of a little time low rpm or higher revs its going to pull out.

It makes no difference if its the 1950s/ 1960s pressed in studs or
1990s pressed in studs they will only take so much and there pulled.
a simple screw in stud stops all that nonsense.

The rpms of the 30/30 cam in the 327/365 cam they were reved past 7000 rpm all the time with pressed in studs for many a mile, but the valve spring pressure on there springs both open and closed was no where near what they recomend for even a hydraulic roller today the lift on 30/30 cam next to nothing .485 compaired to common 540/560 rollers, my point here rpms are not everything they did not do in the old solid lifter factory engines, but I have the cuss words down pat the scrapped knuckles from trying to increases spring pressure just a mild amount on pressed in studs.

I had a friend had an old impala dead stock 348 they did not rev anything pulled pressed in studs. GM should be shot for some of the bullcrap they have put off on people, but there not the only company.

My brand new 69 Z/28 had 18,000 miles put on it when the pressed in oil pump screen fell in the pan ruined the engine dealer replaced the crank two rods under warranty,12 yrs earlier my grandfather had a brand new 57 buick pressed in screen fell in the pan buick replaced the engine. 12 yrs later with my 69 gm had done nothing to fix the problem, things like this things just done half a-s is why gm is where its at today along with other american car companies.

Last post for a few days leaving town.