GAS FLOW & PRICES (all models)

With all CJS cylinder head preparation you get your heads thoroughly cleaned, re-shaped intake and exhaust ports, matched manifolds, polished and modified valves and in some cases modified combustion chambers.

With CJS "Ultimate" heads you receive all of the above but with the addition of new special shaped Colsibro valve guides for longevity, valve seats machined to competition profiles to maximise flow, and optional flow bench data at extra cost.

Some jobs may be refused unless new Colsibro race guides are fitted for reliability reasons. This always applies to 2v heads of the 8mm valve stem generation.  No 2v head with 8mm stems will be worked on unless guides are fitted.

All heads will be thoroughly cleaned ready assembly by us of yourself.  Gas flowing or cylinder head re-working is always updated with the newest realisations based on extensive flow bench and dyno research.  Please keep in mind the heads are not a simple one fits all application.  Each head is a one off and is re-designed to its cam/engine combination and purpose based on customer requirements.