The Edelbrock #61029 Performer RPM Cylinder Head for 1965-76 Oldsmobile 400, 425 and 455 CID V8 engines with hydraulic flat tappet cam is a perfect performance upgrade for big-block Olds-powered street machines and muscle cars. This aluminum cylinder head supersedes the 60519 Olds head and features a redesigned 77cc combustion chamber, larger intake valves and refined bowl blending for improved flow. The #61029 Performer RPM head has improved accommodation for a factory-style mechanical fuel pump with spark plug locations moved slightly towards the exhaust valve for optimized combustion. Intake and exhaust ports have been improved over previous designs, and extra material has been added above the intake port for head work. Performer RPM #61029 heads are cast and machined by Edelbrock in the USA and comes complete with the highest quality intake and exhaust valves and valve springs.