Topband: Height of Beverage-Driveway

[rfman45]

 After 50 years in radio I'm starting to enjoy myself on Topband and have learned much valuable information here thanks to all of you. I have, however, encountered a problem for which I would ask your opinion.
 
 I'm running a beverage about 10 feet high which must cross a driveway. Now 10 feet is too low for the occasional truck so what I would like to know is what would be the effect on performance if I raise it to 13 feet or so just to clear the driveway? I know that beverages can have dips and irregularities but would this three foot increase in height for about 10 feet be an issue?
 
 Thanks in advance for any help on this question!
 
                                73 es DX     Mike   W2LO