Duncan_GT

How much of a benefit are main girdles? Is it really worth the extra cost?

deathsled

I would imagine they are most needed with supercharger or turbo applications or if you plan to race the car and stress the engine.

mjr46

main girdles don't really do jack but keep all the parts from scattering all over the road, they won't stop cap walk, best thing you can do is add main studs and call it a day, I run one but all it does is give me a false sense of security, I know it won't strengthen the block any, with a 351 block you're running, you don't really need one, just main studs, caps are heavier and webbing is much better on the 351 vs 302......600 hp on a 351 block with ease

Duncan_GT

Thats what i figured. I keep seeing them over on the corral for sale. What about a valve stud girdle?

tinman

Rocker stud girdles are another whole story.
They can really do something if you are running a solid roller cam with .620-.640 lift like I do.
They will keep the rocker studs from deflecting all over the place so you don't lose lift.
The main studs are a good idea too but you need to have the block line honed before you can really use them as studs will change the mian bore some, not much but some.
The main bores need to be round as possible as well as inline with each other.....

jtgerik

main girdles are simply designed to keep the block from scattering pieces all over the place when the block splits.. just simply a safety device to keep the disaster to a minimum.. it won't make your block any "stronger" or more "durable".

tinman said it.. valve train girdles will help keep deflection down on hard core cams.. may need one.. may not.. depends on what your cam is..

definitely do the main studs.. ARP makes great ones.. you will need to line hone the block.. When you go from a stock main bolt to an arp stud, the housing bore size changes dimension because of the clamping force/load of the stud vs a stock bolt. and if changing the caps, unless you get lucky when changing caps, you align bore the main tunnel then align hone it to size.

Duncan_GT

Yeah i switched to main studs and already had the block align honed w them. I have a hydraulic roller cam with .613" lift. Would you think the stud girdle is needed?

mjr46

^^^^on the issue of valley girdles, they are truely a waste, cracks start at the bottom under the cap in the 302 stuff and work their way up to the valley.

tinman

I think that you can probably get away without the rocker stud girdle as your hydraulic roller isn't using anywhere near the spring pressure that my solid is.
I'm at 210# at 1.90 tall, over 575# open from there.........

jtgerik

I agree with Tinman again.. I think you can skip it.. that's not to say if you can afford it, it's necessarily a waste.. never hurts to be sure.. except for the bank account lol..