>>> GM PERFORMANCE PARTS BIG-BLOCK HEADS
CAST IRON
Casting No. Part No. Intake Port Combust Valve Dia. Notes
    Volume/Type Chamber In/Ex
14097088 14096802 325/R 118 (o) 2.19/1.88 G5 HO replacement, bare casting
14097088 14096801 325/R 118 (o) 2.19/1.88 14096802 complete assembly
6272990 6260482 325/R 118 (o) 2.19/1.88 LS6/LS7 replacement
3964291 3919839 325/R 108 (c) 2.19/1.88 Closed chamber replacement head
Aluminum
3919842 3919838 325/R 107 (c) 2.19/1.84 L89 1st design service replacement
14011077 14011076 295/R 118 (o) 2.19/1.88 L89 2nd design, C-port
14011077 14011004 295/R 118 (o) 2.19/1.88 Same as above but solid casting, no water jacket
14044861 14044862 380/R 105 (o) 2.19/1.88 '84 Bow Tie, rectangular exhaust port w/vane (W-port)
14044861 14044861 380/R 105 (o) 2.19/1.88 Machined 861casting, no valve seats/guides
14044876 14044861 380/R 105 (o) 2.19/1.88 Raw 861 casting, unmachined
10051128 10051128 400/R 72 (so) N/A '87 Bow Tie symmetrical port, no valve
          seats/guides, round exhaust ports
10051129 10051129 400/R 72 (so) N/A Raw, unmachined version of 128 casting,
        355-T6 material
10049875 10049875 376/R 83 (o) 2.28/1.88 Pontiac small port head
10045427 10045427 460/R 91 (o) 2.40/1.90 Pontiac large port head
N/A 10093386 365/R1 61 2.40/1.90 Pontiac head w/ spread intake ports
12363401 12363408 315 118 2.19/1.88 NHRA-legal L88 replacement
R- rectangular; R1- rectangular with rounded roof; (o)-open chamber; (c)-closed chamber; (so)- semi-open chamber