Quote:
Originally Posted by Tom
The ramjet has .481" lift on the exhaust. .420" lift is the factory spec for a 96-98 vortec truck camshaft, not the limit of the head. That article is just plain wrong.
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Tom were not sure what the Ram Jet specs are - the head part# they list is for a bare head - so it may be machined, they may be using non-standard springs and retainers to compensate, or at the very least they are measuring the clearance on each head to be safe you would hope, but who knows, chevy performance has a lot of wonky engine cam combinations that are a very bad idea like the 350/290. If those are truly stock Vortecs with standard springs etc it would be really interesting though for sure.
Here is another article with pictures of actual head measurements - so this particular vortec they have their hands on cannnot handle more than a .420 lift;
"The stock Vortec iron head will not tolerate more than 0.440-inch lift. We measured our stock iron heads right out of the box and the retainer-to-seal clearance was only 0.470-inch. Subtract the standard 0.050-inch clearance,
this leaves only enough room for a 0.420-inch lift cam. "
http://www.powerperformancenews.com/...benchtop-mods/