Our Advice
We don't regularly run fuel-injected engines on the dyno, so we had a really steep learning curve during this process. To do a job like this yourself, we highly recommend the following:
Buy a factory service manual. Get one for the car your engine came out of. We would never have gotten our engine running without it.
Budget extra money to replace sensors. We had replaced the OptiSpark cap and rotor, thinking the optical trigger was still good. It wasn't.
Be prepared to buy an extra ECM. Our original one never worked, and our replacement got burned up once during reprogramming. They cost about $125.
Plan on engine or chassis dyno-tuning if you replace your heads or cam. There is a lot of learning capability built into the factory ECM, but those parts will alter the amount of airflow through the engine to levels that are greater than the ECM can handle. You'll need to tune it to get the most power from your new parts.
Click here for the LT1 dyno chart
Test One
Stock LT1 355 CID 10.5:1 compression ratio
Iron heads--54cc chambers
| Intake valve | Exhaust Valve | Intake Port |
| 1.94 | 1.50 | 170cc |
Cam specs ('94 Chevrolet B-body)
191/196 degrees duration at 0.050-inch tappet lift
0.418/0.430-inch valve lift
111-degree lobe-separation angle
Test Two
Edelbrock Performer LT1 heads--54cc combustion chamber
| Intake Valve | Exhaust Valve | Intake Port |
| 1.94 | 1.55 | 170cc |
Edelbrock Performer-Plus cam
218/218 degrees duration at 0.050-inch tappet lift
0.525/0.525-inch valve lift
112-degree lobe-separation angle
Test Three
Edelbrock Performer Air-Gap intake
Edelbrock Performer XTreme cylinder heads--54cc combustion chambers
| Intake Valve | Exhaust Valve | Intake Port |
| 2.02 | 1.570 | 195cc |
Edelbrock Performer-Plus cam
218/218 degrees duration at 0.050-inch tappet lift
0.560/0.560-inch valve lift*
*RPM XTreme heads tested with 1.6:1 ratio Harland Sharp rocker arms
112-degree lobe-separation angle
Dyno'd at Westech with long-tube headers
Test Four
Same as above but with custom-ground Comp Cams camshaft and ECM tuning
218/224 degrees duration at 0.050-inch tappet lift
0.570/0.565-inch valve lift*
*RPM XTreme heads tested with 1.6:1 ratio Harland Sharp rocker arms
117-degree lobe-separation angle
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