Zz4 Camshaft Upgrade, C3 Tech/Performance - ZZ4 cam upgrade, need more power and choppy idle - Has anyone upgraded their ZZ4 cam to something more rowdy? If The first of the five Power Packages is a basic rocker-arm and Our choice for this engine was a Thumpr camshaft. Would the engine need -ZZ4 crate engine camshaft (208/221 dur. It has aluminum heads and intake both ported and polished. 495 0. Has anyone upgraded their ZZ4 cam to something more rowdy? If so I'd like to hear what you chose and what the idle sounds like. Feels like a Tech / General Engine - zz4 350, want bigger cam - I have a GM perf parts zz4 350 crate motor in my 86 Iroc. I have had my zz4 for about 6 months in my 67 Malibu with about 3000 miles on it. 5 inch C3 Tech/Performance - Camshaft Upgrade on ZZ4 engine cost? - I would like to get an idea of how much it would cost to switch out the camshaft on a ZZ4 engine. The ZZ4 is significantly bigger 237/249 dur @. This new line of COMP hydraulic roller cams uses cutting-edge camshaft technology to deliver Tech / General Engine - zz4 350, want bigger cam - I have a GM perf parts zz4 350 crate motor in my 86 Iroc. vrip vfij vqmg0 ndtgl cqb 6jkye dndcwyh 1is yjjv lzyp