i to had same issues you have but after spending big dollars chasing power and economy i ended up getting a low km tb45 and i put tb42 rods in it freshened up the rest stuck a gt3582 on the side recond the trany with a shift kit put a manual lockup switch on it and i now have a more powerful and better economy and heaps of fun off rd dont spend big dollars on the standard tb42 you won't gain much they go hard with a turbo on it i was just lucky to come across a tb45 with low km and cheap you may need a lift kit with 33 i did but my suspention was a little sad when i bought it .
good luck
cheers