Some 398 heads have BCP, some have SCP. Same with the 160 heads. The change in coolant passage size occured sometime during the 1984 model year. The 398 heads were introduced in the late '70s when the early 160 heads had erosion problems. At the same time, Volvo started using the updated aluminum alloy on the 160 heads. So, there really isn't any difference between the two, except for the casting number.
LH-Jetronic versions and years:
1.0 - Some 1982 B21F engines, typically late production, and California spec.
2.0 - 1983-84 B23F with 503 or 510 ECU. Uses cube relays for fuel system and fuel pump. Chrysler ignition box (Volvo p/n 1317295 - high compression B23, 1346105 - low compression B23)
2.1 - 1984.5 B23FT with 507 ECU and EZK102K, first version with white fuel system relay.
2.2 - 1985-88 B230F, 1985-89 B230FT, various ECUs used. 511, 544, 554 are non-turbo, 517 and 541 are turbo. 240 used Chrysler box - two or three different part numbers on these as well. 700 used EZK115K or 117K. 2.2 was also used on the B280F in the 760/780/very early Euro spec 960 (like 1990-91), which used the B280 instead of the B6304 engine.
2.4 - 1989-98 B230F, 1990-98 B230FT, 1989-91 B234F (probably B204FT/GT as well, in addition to B200F/FT, etc), again, various ECUs used. EZK116K ignition.
3.1 - 1990-93 B230F with M47, typically in 240 with M47. Uses heated film AMM.
Benefits of upgrading to 2.2 from 2.0:
Cheaper and much more common AMM that's also more reliable
One single fuel system relay, instead of the two power window relays that are used for the fuel system and the fuel pumps
Gets away from the Chrysler ignition system that doesn't seem to work as well in turbo applications
There are some other improvements that you'd notice by upgrading. Not to mention the fact that Dave Barton already has a conversion harness that can be used for turboing an LH 2.2 240.
-J