If you want reliability you need a 3.5,any of the bigger bore engines can suffer problems with loose liners/cracked blocks.If the engine you bought was cheap you can be fairly sure it wont have had stepped liners fitted - its an aftermarket mod and is quite expensive.the guy that sold it to me said it didn't hane a number because the block was changed during a re-build. So no number, sorry. He also said it had a tvr hi-lift cam fitted too, and new lifters and timing gear. Which makes sence to me so i had no reason to doubt him. I wanted a 3.9 because they have top hat liners and are more robust. ( no pourosity issues with the liners), any info would be good. Cheers, big col.