If you have a B20A and you'd like to get rid of your stock ignition coil and the exhaust cam sensor housing or if you want to use B18A/B camshafts without cutting a slot in the exhaust cam for the sensor, you can use a B18A/B (integra LS) distributor with small modifications.
As far as space goes it's just perfect on the B20A to fit an LS dizzy, it clears everything on the head, and also 1 of the 3 mounting ears will fit with no mods. All you have to do is grind/drill out the 2 other mounting ears to fit the B20A head.
Depending on what OBD youre running on your B20A there's 3 different B18A/B distributors you'd have to choose from:
OBD-0 : uses two round connectors
OBD-1 : uses two square connectors
OBD-2 : uses 1 square connector
(this goes for other Honda distributors as well)
While you're at the junkyard grabbing one of these distributors remember to get the other ends of the wire connectors with you as well so you'll be able to wire it up cleanly.
The B18A/B spark plug wires will also fit your B20A if you wish to use those as well.
If you want to use B18A/B camshafts you must be aware that you need to remove approximately 4-5mm of the camshafts in the cam gear end of the cams, otherwise the timing belt could walk off the cam gears since it will not be situated in the center of the gears.
Pics of an Integra LS distributor and plug wires mounted on a B20A:
I will be making an aluminium block off flange that will cover the gap from the now missing exhaust cam sensor housing and seal it off but you can also just put in a plug as used on B18A/B engines if you dont care too much about looks.
When I get the distributor modified and the block off flange done I'll post up some new pics.
Please note that a distributor like this is not needed to be able to use the ordinary OBD-1 ecu's, the stock B20A distributor will do that job fine for you as well.