Beginning in 1980 the 60 degree V6 used a cast iron cylinder head with 40.64mm (1.60") intake valves and 33.02mm (1.30") exhaust valves. This first generation of cast iron head only receive 1 upgrade and that was the addition of 43.69mm (1.72") intake valves and 36.07mm (1.42") exhaust valves on the HO carbureted engines and later all fuel injected engines using cast iron heads. Both valve sizes use an 8.73mm (11/32") valve stem. The intake valve uses a stem seal for oil control the exhaust valve does not. Cast iron heads utilized a conventional rectangular shaped port on the intake side with the addition of a vane on the port floor that helped increase flow. The exhaust port was a round port. The valvetrain uses 6 inline valves on each cylinder head. This valvetrain layout is very similar to a small block cylinder head. In fact the rocker arms, (minus the rocker ball) valve springs, retainers and valve locks from a small block could all be used on a 60 degree v6. The combustion chamber on a cast iron head is a conventional open chamber with a centrally located spark plug. The chamber measures approximately 50cc.

In 1987 with the introduction of the generation II engine the 60 degree V6 saw the addition of a new aluminum cylinder head casting. This head used the same valve size on both the intake and exhaust side as the cast iron heads. The intake port was revised and the vane in the port floor was now gone. The biggest change to this new casting was the change to a splayed valve configuration. This layout finds its roots in the famous big block Chevrolet. The intake valve now moves away from the cylinder wall when it opens effectively un shrouding the valve and promoting increased airflow. The second improvement to this new cylinder head is the heart shaped "fast burn" cylinder combustion chamber which promotes turbulence and cylinder filling for a better burn and a quench area for reduced detonation and cooler cylinder head temperatures. The combustion chamber now measures 28cc. The rocker arms are still the same but the valve springs, locks and retainers are new designs. The valve stems are now 8mm (.315") and use a valve stem seal on each valve for oil control.

In 1993 Chevrolet introduced the third generation of the 60 degree V6. Again the cylinder head casting was revised, this time only slightly. The casting was still aluminum and the valve layout was the same as the generation II casting. The intake port was slightly revised, but the exhaust port received a significant change to a D port shape to increase flow. In 1996 the 3400 motor was introduced and this head saw and intake valve size increase to 44.70mm (1.76") later in 2000 all engines started using this new valve size. All third generation motors use a new valve spring design and retainer.

All 60 degree V6 cylinder heads can be bolted to any pushrod block. However because of the difference in combustion chamber size the corresponding pistons must be used. Intake manifolds are not interchangeable either due to the bolt pattern and the port configuration between the heads.

For mild performance applications the intake ports should be gasket matched and the valve bowls blended into the ports. For high performance applications traditional porting methods can be applied.

High performance valve springs can be installed on any cylinder heads you choose. Gen I and II heads use the same springs as a  traditional Small Block Chevy. Gen III heads can use the same beehive springs designed for a Gen III/IV (LS Series) Small Block Chevy. It is also possible to convert Gen I and II heads over to beehive springs by using aftermarket small diameter retainers.

 For iron heads applications it is possible to install valve guides to allow the use of 8MM valve stems from late model engines. The less valve stem in the port the less of an obstruction they present. Viton valve stem seals from a Small block Chevy can be installed on iron heads with 11/32 valve stems on both the intake and exhaust valves to improve oil control on the exhaust valves which normally do not use any seals. The oil shedders under the valve spring retainer should be discarded.