Valve Springs

[streetstang67]

I'm about to get a cam, but I dont want to change valve springs. First off, I dont really know whats involved, and second, it seems complicated. Either way, it would be nice to keep the same stock springs with the cam change. Right now I'm thinking about the XE256H and a similar specialty cam, the lift for both is around .474-.477. Can I keep my stock valve springs(the engine was rebuilt less than 5000 miles ago)? What are the chances for one to break?

 

[NorCal66]

Someone can correct me if I'm wrong, but I beleive stock springs are good til .500 lift...unless they're old springs in which case you should definately replace them. I need to do mine soon so I'm not afraid to rev it over 4k

 

[1973mach1]

I was going to replace mine and add a bigger cam until I decided to go with the 4bbl 351c heads so now im just doing it all before I install them. I was told you should ALWAYS replace the springs with a new cam. I heard the easiest way to do it is buy a tool that screws into your spark plug hole, it hooks up to a compressor and fills the cylinder with air so the valve doesn't drop when you take off the retainers. Then you compress the valve spring, remove the locks and retainers and pull the springs. Compress the new springs, put them on, install the retainers and locks and your set from what I understand. I heard you have to get them the right height but I have no idea how hard that part is.

Jim