HKS make a Drag Engine, I believe it is a different block.
This is the engine that Reese McGregor (fastest GTR in the world...And a Kiwi!) and the HKS GTR (was the fastest in the world) use.
.....But unless this car cost you a bomb....I don't think you have one, A HKS Drag block sold in NZ for $30k a while back, And that was cheap!
Do a seach, There was something said about it