I changed out the carb on my 455 tonight, I bought a correct 1970 carb from Henry White (by the way the carb works fantastic, I truley believe I may have gained 20-25 hp over the old carb and it runs much cooler!!!!). Ok , when I put the vacuum hose for the power brakes back on the carb, which was at the rear, it now feels like I have absolutely NO power assist on the brakes. 2 feet required to stop from 35 MPH. Can I disconnect the vacuum hose from the back port, and redirect it up to the large one up front. Or what could I have done wrong during the installation? Any assistance at all would really be welcome about now. Thanks , Mark Lob
Bruce, I have taken the hose off the back of the carb twice and re-sealed it to make sure there are no vacuum leaks. I am at a loss for what to do next. You know me and wrenchs...... Mark
Call me if you can , I will try to help Mark . Carb spacer in correct if one is used ? Call me if you need more advice . p
Mark, Pull the fitting out of the booster with the line connected to it, start the motor, and make sure there is a whole bunch of vacuum there.. Then take the fitting off, and just see if the hose has vacuum. Then take the hose off the carb, and see if there is vacuum there.. Could be a port in the carb that is not open. Typcially, vacuum for the booster is drawn right off the rear of the manifold, in number 5 intake runner. Change it to there if you have a problem with that carb outlet. All Dual plane manifolds have that vacuum hole for the booster. JW
Jim, I did as suggested, There is a good amount of vacuum off the rear port of the of the carb. The vacuum hole on the rear section of my manifold has zero vacuum (I am using the poston S-Divider). I ran a hose directly from the carb to the brake booster this time and it seems to work fine. Can I just block off the vacuum hole on the rear of the intake manifold with out causing any problems, and just run a hose directly to the booster? Thanks, Mark
