I'm pretty sure I was not on this forum in 2013 and some people might think that's a good thing but.....(I just read it as results form a search I did on tuning the B30 engine)
I have seen other posts in other threads maybe on other forums cant remember where saying tuning the B30 is futile
they say the crank and block wont handle the power produced etc,
now I have read some dubious posts on forums in my time but that just take the
cake. the block is immensely strong as is the crank.
The standard cranks used in the cars were the same ones in the Penta motors
in Marine applications at a totally reliable 170HP
the standard 164 was between 145HP and 160HP,
depending on the year and fuel system and cam. these power figures are comparable with other 3 litre 6 cylinder motors of the era like the Ford Essex 3.0 and others, in fact the Volvo was more powerful and stronger than most of that era on par with the Mercedes Benz engines of the time, So personally I would tune the B30 because as mentioned earlier an engine swap takes away from the classic status and character of the car.
There are no stroker kits or posh cranks for the B30, as far as I can find there is some for B20 motors to get 2.5 litres and a 3.0 litre B23/B230
https://www.youtube.com/watch?v=W4b28ZScLjM
this video just shows what can be done with a B30
The B30 in this car is running a power output of 644HP and 800nm of torque (in the comments as an answer
from the owner to a question asked about the power output)
yeah just so you read that right SIX HUNDRED AND FORTY FOUR,
easier too because its in the car already. Also there have been plenty of 164 club rally cars pushing out 200HP+ in Sweden Finland Norway etc a great sounding engine
https://www.youtube.com/watch?v=IlRjIHeykls
probably the best classic Volvo tuning site in the world loads of good stuff for the B30...
https://www.kgtrimning.org/1.html?
just wish my 164 was manual but I do have the column shift automatic though a cool combination
but not as cool as the column shift manual M400 combination, yes it exists but not really that good for performance driving, all the parts are shown in the parts catalogue for the 164 ..if only I could find them for sale...(dreaming)