OVERSIZE 1Designed for 1986-91 Tuned Port Injected (T.P.I) 5.7L small-block Chevy Corvette engines originally equipped with centerbolt valve covers. Performer centerbolt cylinder heads are 50-state street legal and accept factory centerbolt valve covers. The intake bolt pattern utilizes the 1986-91 (straight) 90° angle on all bolts. Spark plugs are angled like stock O.E. heads.
| Combustion Chamber Volume: | 60cc |
| Intake Runner Volume: | 165cc |
| Exhaust Runner Volume: | 65cc |
| Intake Valve Diameter: | 2.02'' |
| Exhaust Valve Diameter: | 1.60'' |
| Valve Stem Diameter: | 11/32'' |
| Valve Guides: | Manganese Bronze |
| Deck Thickness: | 5/8'' |
| Valve Spring Diameter: | 1.46'' |
| Valve Spring Maximum Lift: | 0.575'' |
| Rocker Stud: | 3/8'' |
| Guideplate: | Hardened Steel |
| Pushrod Diameter: | 5/16'' |
| Valve Angle: | 23° |
| Exhaust Port Location: | Stock |
| Spark Plug Fitment: | 14mm x 3/4'' Reach, Gasket Seat |
| Valve Lift | Intake | Exhaust |
| .100'' | 64 | 54 |
| .200'' | 122 | 96 |
| .300'' | 177 | 124 |
| .400'' | 217 | 147 |
| .500'' | 229 | 166 |
| .600'' | 232 | 175 |
| .700'' | N/A | N/A |
| Flow Numbers as tested by Edelbrock's SuperFlo SF-1020 flow bench @ 28'' H2O | ||
Technical Notes: Recommended spark plugs are Champion RC12YC or equivalent 14mm x 3/4" reach with flat gasket seat.
| Make | Model | Years |
| Chevrolet | Corvette | 1986 - 1991 |
