From one of my spreadsheets (it was created in 1995), some data updated to include head markings on hardware that I have. Many bolts I have did not have any markings but they may have already been replace before they were removed and I acquired them. The bolts with a UNK head marking I do not have. Note that they are the shorter bolts, I can't explain why. AMK supplies all the bolts in kit form, but does not sell all as individual items, hence NONE for the AMK stock number.
I numbered my bolts starting at 1 from the 12 o'clock position, AMK started at 4. Sorry for the weird spacing, it's a long story.
HOLES IN ALUMINUM WATER PUMP NUMBERED FROM TOP CLOCKWISE WHEN FACING ENGINE
HOLE/
NOTE P/N DESCR HEAD MKG END USE REF AMK
1 A 376256-S2 5/16-18X1.0 HEX,FLANGE UNK TO TAP IN TIMING COVER AM0155P02,3 B-12507
2 42959-S7 5/16-18X1 3/8 HEX,PLACE UNK TO TAP IN TIMING COVER AM0155P16 NONE
2 354033-S2 5/16FLW,0.344ID,0.750OD,0.156T N/A TO TAP IN TIME COV W/O P/S AM0155P02,3 B-12996
3 376258-S2 5/16-18X3 7/16 HEX,FLANGE,GR5 R, G WITH L TO ENG THRU TIME COV SER,MEAS B-12711
4 379681-S8 5/16-18X3 11/16,HEX,PLACE,GR8 UNK TO ENG THRU TIME COV AM0155P16 NONE
4 354033-S2 5/16FLW,0.344ID,0.750OD,0.156T N/A TO ENG THRU TIME COV AM0155P16 B-12996
4 377958-S8 5/16-18X4 35/64STUD,HED CTR N/A TO ENG THRU TIME COV AM0005P47 NONE
5 B 376256-S2 5/16-18X1.0 HEX,FLANGE UNK TO TAP IN TIMING COVER B-12507
6 B 376256-S2 5/16-18X1.0 HEX,FLANGE UNK TO TAP IN TIMING COVER B-12507
7 NONE 3/8-16 TAP,7/8 DEEP N/A FOR ALT ADJ BKT
REF 1 3/4 WATER OUTLET
8 300958-S8 5/16-18X5.0 HEX,GR 5 GR 5,R B W TO ENG THRU TIMING COVER AM0155P10,11 B-10173
9 NONE 5/16-18 TAP 3/4 DEEP N/A FOR GEN ADJ BKT
10 376258-S2 5/16-18X3 7/16 HEX,FLANGE,GR5 R, G WITH L TO ENG THRU TIMING COVER SER,MEAS B-12711
REF BYPASS HOSE
11 42966-S8 5/16-18X2 1/4 HEX,PLACE,GR8 RSP 8 TO TAP IN TIMING COVER AM0155P10,11 B-12685
REF TO HEATER
NOTES
A: ALSO FUEL LINE BRACKET
B: RECOMMEND SEALANT ON TIP