Hi I wanted to know what I would do to swap my (b230f) in my 740 wagon to the 175Hp (b230ft) and if I could use the same tranny and diff. Thanks

Like dylant says, it's probably a WHOLE lot less trouble to just sell your NA car and get a turbo model that you like... around here anyway, there are always a lot for sale. I like to check out www.bargainnews.com for deals. Always lots of Volvos in there.
But YES, you could do a swap. You'd want to have the complete engine, and you should get the transmission as well. You have an AW70 automatic- the Turbo has the AW71 which is more heavy-duty. They do interchange. The dirveshaft and rear axle don't need to change.
You would want a parts car, I would think. You'll need the intercooler, hoses, shroud, airbox, battery cables, wiring harness, oil cooler, computers, and instruments from the donor car. You should also upgrade at least the in-tank fuel pump to the higher-volume turbo unit.
This is all going to cost a lot of time and money... maybe more than you want to spend.
Perhaps a more reasonable approach would be simpler upgrades to your car: IPD sway bars, strut braces, a VX cam, bigger tires and wheels, and a turbo grille for a different look. All makes the base model 740 a lot more fun.
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Rob Bareiss, New London CT ::: '86 244DL- 215K, 87 244DL- 230K, 88 744GLE- 198K, 91 244 180K

I guess the first question is auto or stick? I think if stick you need to change the clutch (good idea anyhow). If auto, ask someone who knows. Differentials don't change, although turbos usually have a different rear end with lower gearing (cheater way to make it faster).

Regardless, it's not an easy swap. Quite a bit of the electrical harness would have to change, as well as vacuum routing, and that's inside the car as well as in the engine bay. Most people would advise just selling your car and buying the turbo you want. I would be one of those people.

All turbo 740s use the 1031 rear end. The 1031 is stronger than the 1030 rear end used in normally aspirated cars with automatic transmission.