hey turbo guys, how do you choose a size?

Since im planning on something cool for my car, i figure ill turbocharge it. Since i play alot in the volvo world, i figure they could be a good choice for a twin setup. The motors are 2.3L, and easily boost 14psi, so i figure 2 would be good at 6-10psi. But for simplicity, how could i choose a single setup. Obviously, a 7.3Lpsd turbo would be too laggy on a 289-302, so what can i do to figure out a good size. Really, im looking for fun acceleration, and not all out drag racing. Thanks.
 
It really, REALLY helps if you know how to read a compressor map and do all the calculations needed to figure out the volumetric throughput of your engine.

The TurboCoupe turbos(x2) work quite well. The '84-86(?) turbo 2.3s had a slightly larger Garrett T3 good for about 275-300hp. Get two and you have the start of a cheap turbo setup that can split your block.

For a single, a PT-38 ball bearing turbo from a later Powerstroke should have okay response and still make 400-500hp. A Holset HX35 from a Cummins 5.9L is in the same league. an HX40, 45, or 50 (or 60 :shock:) is when you want to start stepping up. Ideally you buy an off-the-shelf turbo that is properly sized, though. I have a really old KKK big single I was going to use, but it was for a diesel and has a sucky pressure ratio and not enough mass flow for more than 400hp. I also have a little IHI RHB5 VF series I'm going to put on a Briggs & Stratton 10hp. I'm still sorting out the analog EFI, though. Yes, fuel injection.

By the way, a single turbo setup is not necessarily simpler than a twin.