Cylinder Head Identification

High crown Daytona piston to suite 'Hemi' head

The earlier 'Hemi' heads of 1967 & 68 had the two small holes to accept the pushrods whilst the pushrod tube (below)abutted a flat surface. They are normally marked with the casting blank number E3991, but later castings E6851 can also be found (possible spares batch).

These pushrod tubes will not fit the later Hemi heads with a single large hole for the pushrods.

The later Hemi heads have a single hole for both pushrods & the pushrod tube to sit in. They can be marked with a casting blank number of either E3991, E6851 or 71-2490 & will accept either the castellated pushrod tubes or those with radial drain holes (which are better for assembly)

This sequence of numbers on the rocker box flange may appear to be useful but it is merely a quality assurance number & of little use in identifying the type of head.

The casting blank number can be of some limited use in conjunction with the other identifying features

An exhaust port with no spigot or internal thread, but with a thick wall as shown is most likely to be suitable for the very late Daytonas that used push-in exhaust pipes

These pistons have a flatter ring on the crown to accomodate a 'Squishband' head

These pre-Daytona spec heads have a 'squish band' as a useful identifying feature. The valve size, inlet port size, valve angle & piston shape are all different to the Daytona specification. The inlet manifold fixings also have a different piitch which means the later manifolds will not fit this earlier head.