| ENGINE | YEAR |
DESCRIPTION |
CASTING # | Part # |
| Chevrolet 8 Cylinder | ||||
| 265 (4.3L) | 94-96 | Vin W, Gen II engines, reverse cooling, MFI | 10208890 | 4943 |
| 267, 305 | 75-79 | 267 all, 305 w/2 barrel Carb | 434 | 4849 |
| 4.8L | 99-04 | LR-4 OHV Aluminum heads, light duty truck, vin V | 862 | 4948 |
| 305
(5.0L)
|
78-85 | 1.840” intake valve, 65cc chamber, 7th bolt hole {1} | 416, 450 | 4852 |
| 82-86 | HO, small 55cc chamber | 601 | 4859 | |
| 87-95 | Center valve cover bolt | 081, 187 | 4952 | |
| 96-01 | VORTEC engine, 4 intake bolts in each head | 12552520, 12558059 | 4959 | |
| 307 | 68-70 | Large spark plug, 1.720" intake valve | 185 | 4855 |
| 5.3L (323ci) | 99-05 | LM-7 OHV Aluminum heads, light duty truck, vin T | 832, 706 | 4948 |
| 307, 327, 350 | 71-73 | Small spark plug, 1.720" intake valve | 339, 991 | 4847 |
| 327, 350 | 68-70 | Large spark plug, 1.940" intake valve | 441, 126 | 4845 |
| 350
(5.7L)
|
71-77 | All Cars & 10 Series Trucks, Small spark plug, 1.940" intake valves | 882, 993, 487, 336 | 4850 |
| 20 & 30 Series Trucks, small spark plug, 1.940" intake valves, 3/8" exhaust valve stems, medium duty truck | 882, 993, 487, 336 | 4850-3 | ||
| 78-81 | 20 & 30 Series Trucks, light weight casting, 1/2" NPT temp sending unit, 3/8" exhaust valve stems, 7th bolt hole {1} | 624 | 4851-2 | |
| 78-86 | Passenger Car & 10 Series Trucks, 3/8" NPT temperature sending unit hole, large intake valve, 7th bolt hole {1} | 624 | 4851-7 | |
| 82-86 | 20 & 30 series Trucks, Small intake valve, 3/8" NPT temp sending unit, 3/8" exhaust valve stems, 7th bolt hole {1} | 261, 624 |
|
|
| 87-88 | Passenger Car & 10 Series Trucks, EXCEPT police, center valve cover bolt, square push rod hole, FI | 14102193 | 4950-S | |
| 89-95 | Pass Car & 10 Series Trucks, round push rod holes, FI | 14102193 | 4950 | |
| 87-92 | Center valve cover bolt, Police, vin 8, w/Carb (not TBI or FI) | 14101083, 14066217 | 4951 | |
| 87-95 | 20 & 30 Series Truck, 3/8” exhaust valve, center valve cover bolt | 14102191 | 4950-3 | |
| 90-95 | Trucks over 8500 GVW, rotators on all springs, center valve cover bolt | 10110810 | 4960 | |
| 92-97 | LT1, vin P, Aluminum, SFI, OBDII | 10128374, 10128649 | 4974 | |
| 90-95 | Corvette, vin J, DOHC 32v, right side | 10106178, 10174389 | 4978 | |
| Corvette, vin J, DOHC 32v, left side | 10106179, 10174390 | 4979 | ||
| 94-96 | LT1, vin P, Gen II Cast Iron heads | 10125320, 12554290 | 4990 | |
| 96 | LT4, OBDII, 53cc Aluminum | 10239902, 1255690 | 4996 | |
| 97-98 | Vin G, LS1, GEN III, Corvette, Camaro, & Firebird, perimeter valve cover bolts | 12558806 | 4997 | |
| 96-99 | 20 to 30 Series Trucks, VORTEC engine, 4 intake bolts in each head, vin R | 10239906, 12558062 | 4906 | |
| 99-00 | Vin G, LS1, GEN III, Corvette, Camaro, & Firebird, center valve cover bolts | 12559853 | 4909 | |
| 00- | GTZ Corvette, LS1, GEN III, 38cc aluminum head | 12480005 | 4905 | |
| 10 to 30 Series Truck, 8mm rocker arm bolts | 10235772 | 4907 | ||
| 6.0L
(364ci)
|
99-00 | LQ-4 OHV, Cast Iron, 2500 Series Truck, vin U | 2561873 | 4973 |
| 01-04 | OHV Aluminum heads | 4975 | ||
| 400
|
71-77 | Small block, 6 bolt exhaust | 4854 | |
| 78-86 | Small block, light wt casting, 7th bolt hole {1} | 624 | 4856 | |
| 396,
427
|
65-70 | 1 bolt alt mounting, closed chamber, long reach spark plug | 215, 136, 854, 063 | 4857 |
| 2 bolt alt mounting, closed chamber | 4842 | |||
| 402, 454 | 70-84 | Open chamber, short reach tapered seat plug | 741, 049, 238, 820 | 4846 |
| 454
(7.4L)
|
85-90 | Small (1 5/8”) intake port | 045, 175, 236, 360 | 4844 |
| 91-95 | Bolt on rockers, center bolt valve cover | 10114156 | 4954 | |
| 96-01 | VORTEC, bolt on rockers, center bolt valve cover | 10141279, 12553266, 12558162, 12560241 | 4958 | |
picture of 7th bolt hole
Also see heavy duty truck