Like my '73 Duster and as clif said in the beginning, it will take some minor modification. The heatsink on the back of these LEDs isn't as taper as the stock headlamp, so to make it fit all the way into the housing you'll need to shave off part of the heatsink to taper the back. I used a cutting wheel on my angle grinder. So yes, they *can* fit into your '74 but you'll need to do a little extra work. The harness for the light will match up to your existing plug, so no fancy wiring needs to be done.