Ok, so i found something interesting about 300 series power steering rack, but first i need some more information.
I found only that picture of 340 rack.

Is it the same rack as in 360, or in 360 was different?
If someone could send, i need better pics of 300 series power stering racks.

I am fairly certain there was only ever 1 power steering rack used

I found that probably this is a steering rack from LHD version of volvo 400 series

And to RHD volvo 300 series would fit a LHD 400 series steering rack
I have one from LHD volvo 460 and i could measure her dimensions (lenght, mounting holes, thread size etc.) but i need someone with original 300 series hydraulic rack to verifty is it the same

Looks pretty RHD to me and looks pretty similar except for the mounting brackets and pipe routes, 360 has an clamp + adaptor.

What is your point?

I'm currently fitting later PS to my older 360.

Interestingly the PS seems very imperial rather than metric (edit to correct this, talking bollocks, 11mm flare nut spanner just didn't fit because the pipes are really close), the hydralic rigid pipe union are not metric (edit- not sure about this either) and the hex screw holding on the PS pulley on the pump is also not metric (between 8 and 10mm). Caused me all sort of tool problems. Also be very careful if removing the pipes, very easy to cross thread the aluminium.

There are a few unexpected model difference (injection vs carb) and additional difficulties with B230FT interference. like the exhaust, but there is room and fibreglass wrap is definately recommended for the exhaust.

Edit to add - I had a carb PS kit and the resevoir return pipe is a bit short for the injection mounting position of the resevoir (it avoids the big fuel filter), needs extending. The carb feed pipe to the pump from the resvoir is best turned around to avoid kinks.
Injection backet is different to the carb brack for the resevoir.

I can't remember the manufacturer but does AC Delco ring a bell?

http://www.acdelco.com/centennial-celebration.html