| GM LT4 |
| Valve | Exhaust | Exhaust | Open |
| Intake | | Lift | w/ pipe |
| 0.050 | 43 | 37 | 36 |
| 0.100 | 78 | 67 | 67 |
| 0.200 | 147 | 109 | 114 |
| 0.300 | 197 | 133 | 141 |
| 0.400 | 230 | 159 | 167 |
| 0.500 | 250 | 172 | 180 |
| 0.600 | 243 | 177 | 185 |
| E/I | | 69% | 72% |
|
| GM LT4 ALUMINUM |
| Port: | 195 cc |
| Chamber: | 56 cc |
| Valve Sizes: | 2.00/1.55 |
| I Flow @ 0.400: | 230 cfm |
The LT4 is substantially different from the LT1 casting, and the flow numbers explain why. The head uses larger valves, but the real reason for 230 cfm at 0.400-inch lift can be attributed to the larger intake ports. For a production engine, these are great flow numbers. Like the LT1 casting, these LT4 heads can be used only on a reverse-cooling LT1 engine but do offer some significant horsepower advantages.
Manufacturer
Air Flow Research (AFR)
Dept. CT04
10490 Ilex Ave.
Pacoima, CA 91331-3137
(818) 890-0616
Ameduri Racing Products
Dept. CT04
2359 Alhambra St.
Norco, CA 91760
(800) 418-9573
Brodix Inc.
Dept. CT04
P.O. Box 1347
Mena, AR 71953
(501) 394-1075
Brzezinski Racing Products
Dept. CT04
N. 50 W. 23001Betker Dr.
Pewaukee, WI 53072
(414) 246-8577
PowerHouse Products
Dept. CT04
3402 Democrat Rd
Memphis, TN 38118
(800) 872-7223
SuperFlow Corp.
Dept. CT04
3512 North Tejon
Colorado Springs, CO 80907-5299
(800) 471-7701
Westech Performance Group
Dept. CT04
11098 Venture Dr., Ste. C
Mira Loma, CA 91752
(909) 685-4767
World Products, Inc.
Dept. CT04
29 Trade Zone Dr., Bldg. PR
Ronkonkoma, NY 11779-7369
(516) 737-0450