ghostrider

Looking for guidance.just bought 77 280z and am undecided about whether to keep the stock engine and get some more hp out of the engine or go with the v8. Need some help on this. Also if I do go with the v8 I want to use the LS1 motor and the borg-warner t56 6 speed tranny. Is this a good combo? I know the automatic tranny would be easier but I like the manual tranny better. Where is there a good place to purchase the LS1 engine. Money is a issue, so would a regular 350 with cast iron block be just as good. thanks