I'm not a VK person, but I have the VH45. It is truly an amazing motor. Aluminum block and heads, 6900rpm, actual power around 310hp 330lbft, forged internals, full crank girdle, 6 bolt mains, low friction pistons, high coolant flow heads, bracing in the valley, other things i'm forgetting. Some people on nico and v8nissans have over 400hp confirmed boosted on factory internals and there is talk all the time of 600hp on stock internals. There were NO manual transmissions offered. there are a couple of adapters that companies offer to hook them up to the 5speed from a 300zx. Mazworx is the company that most people seem to go to. apparently their product is great, but their customer service sucks. I would go to nicoclub(dot)com to find out more info about the two engines you are interested in.