Originally Posted by quicksilver67
I'll tell you from experience, you need to get the heads worked on. The Vortec heads will not accept a cam with more than 400 lift. After several broken springs and pushrods I found an article on Super Chevy that explained my problem. Heads must be worked on.
Sorry quicksilver, but you might want to read that Not-so-Super Chevy article again! Most vortec heads are good for .420-.460 lift! The Vortec's I had on my truck varried between .450-.465 stock. I ran the exact cam in my truck, with factory (very) tired valve springs for a year with no problems! Is it best to run factory springs on these heads in factory form? Probably not. Is it possible? Yes. You just have to check your retainer to seal clearance!