The dual 8 inch will only be a little better at best, if you want to upgrade swap in a hydro boost unit.
Found this in a search.
Originally Posted by POWERBRAKEBOB
The Problems With The "wonder Booster", The 8" Dual, Is That It Is Measured At The O.d. Of The Crimp. The Rear Dia Actually Is 7" Dia, And The Front Dia. Is Actually 5.5". The Inside Hub That Supports The Dias. Is A Larger Than Most Hubs, And Further Reduces The Dia. Area. If You Have Normal Vacuum, This Booster With A 1.125" Master Will Push The Pressure Guage Only To 850 Psi. Disc Brakes Like 1200psi And Over. The Popular 7" Single Dia Will Only Reach 450psi. We Like The Hydroboost System, Because It Can Deliver Up To 2000psi, With A Normal To Great Pedal Feel. They Can Be Bolted Directly To The Firewall, And Eliminate The Bracket Extensions. Almost Any Master Can Be Used. On Frame Mounted Brake Boosters, They Are Flat Underneath, And The Big Exhaust Pipe Can Be Run Alongside, As The H/b Is Oil Cooled. They Also Can Clear Those Huge 572 Motors, Hemi's, And Others With Tall Valve Covers. Vacuum Is Not An Issue, As It Receives It's Pressure From The P/s Pump. Any Cam Can Be Run, Any 4 Disc Combo Can Be Used, And They Can Stop 1000hp Cars. "powerbrakesonline.com" Has Many Photos Of Installations, Featuring New Hydroboosts. If You Do Shop Junkyards For Used, They Can Rebuild Them, And Provide Stainless Hose Sets To Hook Them Up. They Can Fit Camaro, Chevelle, Mustangs, Street Rods, Jeeps, And Trucks.
Edited by 71BLACKSS454 (05/29/11 11:37 PM)
One owner 1983 MC 40,000 miles. Our very first new car.
Third owner 1971 SS454 Monte Carlo, one of 1919 built.
2014 Silverado High Country 6.2
2013 Equinox daily commuter
2015 Equinox wife's car