The galactic cosmic ray intensity at Pioneer 10 has been compared to that at Pioneer 11 over the respective ranges of heliocentric radial 9<r10<9.0 and 1.0<r11<5.0 astronomical units (A.U.) during the period April 1973-January 1976. The dominant variation is a coherent temporal one with a peak-to-peak amplitude of about 35 percent of the mean. A further cyclic variation of about 8 percent peak-to-peak has a 26-day period and is attributed to solar-corotating interplanetary magnetic field structures. After detailed time-lag analysis the ratios of intensities at the two spacecraft yield a radial gradient G=+2.0 (¿0.5) percent per A.U., integral above a particle energy E=80 MeV/nucleon and over the differential radial distance range 1.2< (r10- r11) <5.3 A.U.