my 2c...which aint much
buy a rb30 bottom end from wreckers (mine cost $100 )
buy an rb25de head (mine cost $750)
do a std bottom end rebuild of the rb30 using same pistons, just hone, new rings and bearings ($850?)
bolt on head to block, drill tap tensioner, $30 timing belt, 2x rb30 tensioners ($80 ea)
how much so far?...using rb20 sump, manifolds, turbo (i am to start ) water pump, rb20 oil pump....no costs here.
redrill engine mounts to lower engine, plug in rb20 sensors, mod front pipe.
done...turn key and watch the rb30 rumble for under 2k.
But as they say...the spending never stops once it starts....i wish i had kept to the plan above and watch people grin
Seriously though i had the same drama as you. Rb20 blew, and went the rb31. Never look back now