1- Starting with the Head The regular head is Cast in aluminum-alloy.
While the Turbo has a stronger, sodium-injected alloy.
2- Also Different materials are also used for the Turbo's valve seats and pre-
3- The Turbo's valves are of a special metal known as Resistal. Also the
Exhaust valves are reinforced by a plasma spray during manufacture.
All the above with an Eye toward the motor working harder and under more heat
The Block and internals are somewhat different also.
1- The connecting rod's on the Turbo have greater piston pin clearance.
2- The pistons are made of a tougher alloy and the skirts are Notched for
clearance with the piston-cooling oil jets that are set in the Block.
3- The turbo also has a oil cooler installed between the oil filter and the filter
4- On Turbo's you also have an added Fan and or added fan speed!