Installed 355 engine.11 inches of vacuum.NOW NO BRAKES.All are stock for 1980 Z28.Any help would be great.Have added extra vacuum can stiil the same.automatic with 3000 stall 3:42 gears 350 turbo with shift kit.

 

More info would help. Do you mean no power assist or do you mean no brakes as in the pedal hits the floor?

Im going to guess, the pedal goes to the floor.

How long was the car sitting?
Do the brakes pressure up if you pump them a few times?
Do you have any fluid?
Do you see any leaks around the drums?
Do you see any leaks around the calipers?

 

Vacuum canister, might help. They're pretty cheap too. Basically they're just a can that stores vacuum to help when you need it.

 

Read his post; he already added a vacuum can.

 

OOOPps. How big is your cam? Tell us about the entire engine combo too. 3.42s are pretty tame. Sounds like you may be over cammed. Or go manual brakes.

 

Engine is 355.flat top,pm rods,steel crank,4 bolt,gear drive,rpm heads and intake,650 dp holley,roller rockers,comp cam 274 extreme 230 intake and 236 exhaust,Brakes are hard as with no power assist I have to gear down to stop.I am guessing not enough vacuum.Car weight is 2915 lbs.Have cut extra weight out of car.Compression is 9.54:1.Rockers are 1.5

 

If 11 inches is your max. vacuum then you may have to go to a vacuum pump. I've got a friend who has a 38 Plymouth coupe with a hemi, and it runs a vacuum pump fort he brakes. They work well, but sound like an electric fuel pump when running. Not cheap at around $300, but they work well!
SSBC 28146 - SSBC Electric Vacuum Pump Kits - Overview - SummitRacing.com

 

Thankyou,I will go that route.Have a great day

 

I don't think your combo is that wild. Maybe a vacuum leak somewhere or not tuned that well.