I put all 4 relays into the box. You can move them around.
The box only has room for 4 relays, though plenty of fuses are left for future projects. If I had to do it again, I woul have the ignition power relay in the box, and FP, HEGO, & ECC relays, under the dash close to the puter.
The 3 left over relays in the box would go for High & low beam headlights, and electric engine fan relays.
Another alternative for housing relays & fuses, looks like an Autolite battery, but is a plastic dummy battery. The real batter goes in the trunk, plastic dummy in the old battery location. Use the battery tray that turns the battery sideways(68?) and you still have clearance for a 24" or 26" aluminum radiator. which you will want, especially if you use the 5.0 serpentine belt system.