I have some info--and a question. The only Greenbook I could find quickly is actually for a 1972 164 but I think this will apply to your B20 head. A deck height of 86.7mm would apply to a B30A - carburetted and a compression ratio (CR) of 9.3:1 . A B30E would have a deck height of 85.5mm and a CR of 10:1. B30F would have a deck height of 87mm and CR of 8.7:1.
My question--you mention the undrilled platform for injectors - but what do the intake ports look like? Are they machined for a locating ring? Or tapered outward as the E & F heads are, with locating pins in the head?
What you have sounds a lot like the head I used on my 1969 B20. My head has the 44mm intakes and flat surfaces where injectors might be located but it has the machined locating rings. I remember calculating (using a B20 Greenbook) it had the lowest CR (8.7). I had it milled .125" to bring it over 10:1 on a B20. The first B20E's came in at 10.5:1 (135hp). When I first built that head it was for a B18 so the CR was lower, more like the '67-'68 US market B18's with 10:1 CR. (108 cu. in.- 115 hp). Sorry to disappoint you if you thought you had a high performance head. I port matched my exhausts and cleaned up them up - left the intakes alone. I've always thought it all worked out well. -- Dave