My motor vehicle can be an early '87 Mk1b and looks to have a wide range of Mk1a stuff on it. I have never checked which block I have still. The engine does rev like a jewel.The five valve head is Toyota's reward to the 4AG after the 4AGZE went absent. With the extra valve and unbiased throttle bodies- the 4AG 20 valve is a unique head layout. This