With a new engine from the S10 the Volvo sizes and positions are irrelevant. For size the rad needs to fit the space without it clashing with the hinges. There are of course 2 styles of these. Alternator positioning can cause problems with both of these. The capacity needs to cool the engine regardless of local ambient conditions. 80 mph across Death Valley at noon for example. Hose size and positioning can be selected for the neatest and most convenient layout. It may need to be custom but many alternate engines have gone into the PV.