Ive got a 1971 buick skylark GS 350 that im considering on making into a stage 2 clone car and I had a couple questions Im not sure if you can help me out on. First off I would want to stay completely buick on this but Im not really feeling the buick 350 thats curently in the car and the urge to just go chevy small block with a turbo 350 sounds really good to my wallet but Im not sold on this either. (1) I know that with most if not all chevys/fords the cross member and front springs need to be replaced when going to a big block(455) and im honestly just not sure with my buick if thats necessary? (2) Im not looking to build a motor for fear of spending 10,000$ and forgetting to install a freeze plug or something stupid, but I have been looking at some pre assembled turn key motors ($10,000) and some others with factory heads close to factory specs for around 3-5,000$ and Im not sure if anyone can recommend a shop that does good work? (3) Once again being new to buicks would I need to replace the transmission by going to a big block? Sorry for asking so many questions but any feedback is greatly appreciated! Im loving my buick and really want to do it the right way.