what kind of vacuum does a ls6 camshaft carry in a 454 and what does it sound like? 10:1 compression. thanks

That cam in my 396 carried about 12 in of vacuum. It sounds just like an L-78 396 since it's the same cam. Maybe a little smoother due to extra cubes. It's a slightly lumpy idle at 800 rpm.

Here are a couple of examples....

On of the reps that calls on us owns a 1967 427/435 HP Vette....Same cams as the LS-6.This is a restored car so it's running the stock cast iron manifolds and factory chambered side exhaust system.The idle is slightly lopey with just a bit of the typical solid lifter clatter...Very easy to live with and not obnoxious in manners and very driveable.M21 with 3.55's obliterates the tires with ease.


One of the customers has a 1967 El Camino with a 396 large oval port engine....headers ... 3 in ex and 40 series flowmasters....same LS-6 / L-78 cam.... In this car the idle sounds a bit rougher....The exhaust system is so loud you can barely hear any tappet noise...TH400 works deciently with the stock converter converter.Tires dont stand a chance in this one either but with this exhaust system it makes the whole truck seem like more of a handfull and less easy to live with... WAY LOUDER and seems alot more peaky and less driveable...... Most likely the ex system is just too large for this combo....

thanks to all of you who replied that exactly what i wanted to know. YOu guys are great......

I have a stock 1990 LS6 crate engine and it has 13 inches of vacuum at idle. Dave