the D16A1 is the 86-89 Integra engine - should be a lot of them around - the 86-87 D16A1 works better in the 1g CRX since it has the vacuum advance ignition instead of the electronic advance found on the 88-89 D16A1, although you could make the 88-89 work - another better option is the 84-87 JDM Civic/CRX Si DOHC ZC "browntop" engine (more hp) - in order to use the D16A1 or the "browntop" ZC, you need to also use the 86-89 Integra transmission, intermediate shaft, axles, knuckles/hubs and shift linkage - all of these parts bolt right in with no modifications - if the CRX is not the Si model, you would also need the complete fuel system (tank, pump, lines, etc.) and most of the wiring from the 1g CRX Si model or 3g Civic Si model in order to run the fuel injection