And avoid the 85 - 89 motors. Volvo was trying a 'low friction' approach to get better MPG, one of the changes was skinny connecting rods. Fine in stock configuration (even Turbo models) but way easier to blow up if you start cranking the boost up. Just a little detonation under boost and the rods can bend or shoot themselves out of the block.Earlier motors were stronger, in 90 they reverted (sort of) back to the earlier design with beefier rods. And, as mentioned, in 93 they added oil squirters which keep the pistons cool(er) under sustained boost.

With the right supporting rods, 250 - 300 hp is doable on a stock bottom end and head, with better cam, turbo, exhaust, injection system, intercooler, injectors, head gasket.

With mostly junkyard parts from various other cars and trucks, my 245 is at around 250 whp.
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'63 PV544 rat rod, '93 Classic #1141 245 +t