The 98 block is a lighter design, and unfortunately grenades when more than 10 lbs. of boost is put to it for any length of time.

The heads are great,

the rods and crank, I don't know :-? . the rods do look good and may be in the same strength area as the 92 to 95 L35 engines. As far as pistons, go with the TRW/Speed pro forged turbo/super charger pistons, or go with some srp's or something of the like if you are not to money tight... The main thing is FORGED TURBO PISTONS of Around 8.3 or less Compression ratio..... No hypercraptetic or the like.... I would select a throttle body injected block/ code lb4, and have at least a set of aftermarket 4 bolt main caps installed (Requires line boring), L35 blocks are good too, but you have a balance shaft setup that restricts you to a different style camshaft than what is run in a sy/ty engine. Head accessories and intake stuff, contact JWaller, and he can set you up with all the vortec stuff, tell you what you need there... As far as the late model
4.3's , I would stick with the Powerdyne/Paxton style belt driven Superchargers with those engines, I think they only put out 10 lbs max...For a reason....