As shown on that page, all 300 sixes from 1980 to 1989 used D5DZ 12A099-A, which is Motorcraft part # DT-6. However, since the prefix of "D5" means that part was created in 1975, it is likely that all 300 sixes from 1975 forward used it. And the only reason I say "to 1989" is that is the end of coverage of the catalog I have, and the "1980/" means from 1980 to the end of the catalog.
In other words, all 300's from 1975 through at least 1989 should have that part on them.
Gary, AKA "Gary fellow":
Profile
Dad's: '81 F150 Ranger XLT 4x4: Down for restomod: Full-roller "stroked 351M" w/Trick Flow heads & intake, EEC-V SEFI/E4OD/3.50 gears w/Kevlar clutches
Blue: 2015 F150 Platinum 4x4 SuperCrew wearing Blue Jeans & sporting a 3.5L EB & Max Tow
Big Blue: 1985 F250HD 4x4: 460/ZF5/3.55's, D60 w/Ox locker & 10.25 Sterling/Trutrac, Blue Top & Borgeson, & EEC-V MAF/SEFI
Locked
)
