Modular Spark Plug Part Number Chart
 

Found this on Socal Tuning's board. Thought it'd be handy. Enjoy!

modular plug chart
MOTORCRAFT

PART# / HEAT RANGE
AWSF-32C / stock heat range - copper plug
AWSF-22C / 1 Heat range colder - copper plug
AWSFA-12C / 2 Hea range cooler - copper plug
AGSF-32C/ Recommended for FRPP heads(not sure on heat range)

NGK

PART# / HEAT RANGE
TR-55/ 3951/ Stock Heat Range
TR-6/ 4177/ 1 Step Colder
BP7EFS (PN - 3526) BR7EF (PN - 3346) two steps
R5724-8 (PN - 7317) two and a half steps
R5724-9 (PN - 7891) three steps
R5724-10 (PN - 7993) four steps

AUTOLITE

PART# / HEAT RANGE
764s / Stock
AR103 / 1 heat range cooler
AR94 / 2 heat range cooler
AR93 / 3 heat range cooler
AR92 / 4 heat range cooler

CHAMPION

PART# / HEAT RANGE
YS-59C / -3 or -4 below stock heat range

DENSO

PART# / HEAT RANGE
IT16 / stock heat
IT20 / -1 heat range
IT22 / -2 heat range
IT24 / -3 heat range

See below for updates.

good catch but if I could add to that: the Motorcraft sparkplugs that start wth "AW" are the 1/2 thread design, which have/are being phased out for the full thread sparkplugs that start wth "AG" the ONLY exception to this is the FFV(flex-fuel) sparkplug AWSFA-12C which is still 1/2 thread and will prob reman that way or be discintinued, everything else remains the same.

so to sum it-up, AWSF-22C is now AGSF-22C, AWSF32C is now AGSF-32C

killer. now we have the update too. :)

They have the same thing on MD, http://forums.modulardepot.com/showthread.php?t=71070