gross valve lift is .595 intake and .580 exhaust

duration @ .020 tappet lift is 278 intake and 282 exhaust.

specs installed @ 108 intake center line

Duration @.050 248 intake and 252 exhaust. i'm new to understanding cam numbers so if someone could explain all the numbers i've listed that would be awesome. if your going to make fun of me i understand that too

 

That is a big cam in my book... the stock cam is only 300 / 307 lift

 

so when i go to put this down in my specs like at the bottom of this box how would i write it out?

also do you guys think this is a big cam for my 397?

 

For a 396 that doesn't look too bad, it would be pretty rough on a stock ci LT1. Here are the stock specs for different years and types of LT1s.

Duration is how long the valve stays open, so if it's a certain duration at .050 lift that means that for that many degrees the valve is at or over .050 inches of lift. Most people only look at .050 duration because the advertised duration can vary greatly between manufacturers.

The lift numbers are the max lift the valve will see with that camshaft. With engine specific cams most of the time the lift numbers will be advertised with the rocker ratio already advertised included. - The LT4 hot cam kit is advertised with .525/.525 lift, which is lift with the 1.6 roller rockers that it comes with.

 

GreenDemon just went to your link I was wrong about the lift #'s i quoted.

 

That's a pretty big cam, even for a 396.

 

thats a good size cam but you could go a bit bigger since you have a good set of heads. some run a 260 268 on 383s and 396s

 

Are we talking about a HR cam still? Once you're in the 255+ duration territory, it makes sense to me to be considering SR. I could be way off though.

 

Actually you're not. Just another reason cam #s can be so confusing.

.300 x 1.5 = .450
.307 x 1.5 = .460

So the numbers you quoted are the actual lift numbers the lifters and pushrods are seeing, whereas the ones I quoted are the ones the valves are seeing. .450/.460 is right on for a 93-95 F-bod or Vette.

 

its a full roller set up with 1.6 magnums.

can you salvage an old cam? there are just a few lobes with one side ground away. thanks

 

what does the 96-97 HAVE?

 

And Again - Go to the bottom of the page.

 

thank you, that was a stupid ?
sorry about that

 

GreenDemon Thanks for the input that makes me feel better.

 

Looks big to me!

Mines' only in the 24X range on each side.

With that tight LSA you're going to have a helluva freeflowing exhaust

Full roller setup, but are you running SR or HR (Solid or Hydraulic) is what he was saying...