I've pressure washed my engine several rimes. I've never cover anything. I just try not to directly spray the distributor. You shouldn't have any issues...if you do then that part should replaced anyway
You can't lose if you put God first!
1989 LX, 306 with TF top end kit, Anderson N-21 cam, TKO 600 trans with steel splatter shield,full Maximum Motorsports Mustang maximum Grip box, Detroit locker rear end with 31 spline Moser axles. Staggered wheels with Nitto 555 315/35/17 out back.