no CR reduction for 5-7 psi... but make a compression test;) (IIRC you redone your engine, right? or it was only the head?)
__________________________________________________________JUNKYARD LIST for those cars provided by a member of hondaswap.com:
GAR= garrett MIT= mitsubishi
SAAB 9000 (16V Intercooled) 87-88 2.0L GAR TB0356
SAAB 900 (16V Intercooled) 87 2.0L GAR TB0339 (Oilcld)
SAAB 900 (16V Intercooled) 84-86 2.0L GAR TB0339 (Oilcld)
SAAB 9000 (16V Intercooled) 85-86 2.0L GAR TB0343
SAAB 900 (8V, APC) 82-84 2.0L GAR TB0321
VOLVO 200 82-84 2.3L GAR TB0313
VOLVO 740 89-93 2.3L MIT TD04H
VOLVO 740 87-89 2.3L MIT TD05
VOLVO 760 89-93 2.3L MIT TD04H
VOLVO 760 87-89 2.3L MIT TD05
VOLVO 780 85-87 2.3L GAR TB0363
VOLVO 780 90 2.3L MIT TD04H
VOLVO 780 87-89 2.3L MIT TD05
VOLVO 940 91-93 2.3L MIT TD04H
VOLVO 200 Watercooled Upgrade 82-84 2.3L GAR TB0368
VOLVO 740 (Oil Cooled) 83-85 2.3L GAR TB0326
VOLVO 740 (Watercooled) 85-87 2.3L GAR TB0363
VOLVO 760 (Oil Cooled) 83-86 2.3L GAR TB0326
VOLVO 760 (Watercooled) 85-87 2.3L GAR TB0363
I know about Garrett, so I'll leave the MITSUs to others

Two interesting turbos from the list:
1)Garrett model number:
TBO363 (T3 series turbo)
Compressor trim:50
Compressor housing A/R:42
Turbine housing A/R:48
HP Capabilities::275hp
Internal Wastegate: Yes
Watercooled: Yes
Wastegate setting:7 psi
2)Garrett model number:
TBO326 (T3 series turbo)
OE part #: 465446-9
Compressor Trim: 50
Compressor housing A/R: .42
Turbine housing A/R: .48
Horsepower Capabilities: ~275hp
Internal Wastegate: Yes
Water cooled: No
Wastegate setting: 7 psi
one is watercooled, the other isn't. They should have a very low boost threshould and maybe they will ran out of stream at high revs when searching over 230bhp-240bhp
3)best bet (increasing boost threshold) would be a T3 60 trim from a merkur xr4ti/SVO, but you need the one with 0.48 A/R STAGE 1 turbine housing, otherwise the boost threshold will be too high as the power band;) this T3 60trim would be enough for 300whp with right tune and a good setup with right compromise between boost threshold and power
SEARCH IT WITH INTERNAL WASTEGATE. you'll save money and an external one will be overkill for only 5-10 psi of boost...
Watercooled is good but not essential.
Eventually, even if it isn't your situation, don't waste money searching T3 Super 60, in this case go or T3 60 or small T3/T4, because there are REALLY
A LOT of speculators that sell standard T3 60 for T3 S60 at huge prices:D
LAST: it's true that there aren't a lot of specifical infos about M42, but the turbo route is always the same for all engines;) so check miataturbo.net section DIY TURBOS (and other honda turbo sites that now I don't remember), they are all 1.6->2.0L max and their engines are near the same when speaking of turbo sizes/spool/threashold.
if you will have a decent piggyback/ecu tune the stock CR will give you no problems. It's all about to learn how things work and then you can do everything
and sorry for thypos, I'm searching to have a better English
