Morning everyone!!

Does anyone out there know what size H4 headlight housings I need to buy to replace the 9004 headlights in my '87 Westy???  I've already done the wiring/relay upgrade and now I'm ready to finish it off.  The only H4 housings I've been able to find are replacements for sealed beams.  I just want the housings and not the bulbs, since I'd like to purchase the bulbs separately.  I also don't need a whole conversion kit, since I've already upgraded everything else.

TIA!
Rod Woten
'87 Westy
Des Moines, IA