Parts List reqd

Hey guys, I wonder if anyone can help out,
Live in Australia and own a 78 Camaro, currently its fitted with a 305 chev pre 68 engine, and yes its very very tired. I purchased a good running 2nd gen 350 and wish to overhaul prior to fitment. Car ways 1650Kgs currently revs at 2150 at 60 miles/hr, when I give it a gutfull it free revs to 4500 and then kicks the gbox down and goes, it also runs on LPG fulltime. It feels incredibly sluggish but sounds good. Okay can anyone help me with a parts list recommendation, my goal is a 300hp minimum engine or whatever people recommend, no blower just naturally aspirated Carby (because of the LPG), rough idle is not an issue. Im after something that will make this old girl get up and go when I give it a bootfull. Im a jet engine mechanic by trade, and Ive rebuilt car engines before, just need some good advice
Thanks Simso

Stuffed up couldnt find my post from yesterday and thought this was it when I did a search on my name please disregard