Have a '71 Camaro and still have the '70 LS6 crate motor (purchased from Nickey's dealership in '71 after the LT1 was blown) installed with all the original parts minus manifold and carb. I have always had concern over the lack of vacuum the motor produces for the power brakes. They work fine when cruising but when I am at a stoplight, it basically is to the floor after waiting for about 10 seconds at the light (not too reassuring). It still has the solid lift cam which I believe has a .520 lift and 316-302 duration. I also have a vacuum can installed which helps minimally and was wondering what type of vacuum booster setup the '70 Chevelle's had with an LS6 motor that failed to produce enough vacuum for their power brakes??? ...and how much vacuum were they producing as I am right around 7-9" at idle while in park.

I do not plan on changing cams as I am very happy with the motor (with only 3K original miles on). Not interested in a noisy electric vacuum pump either.

Thanks!