Early 360s had flat top pistons. Ditch the 600 holley and get a 750. the LD 340 intake will work fine. Use steel shim headgaskets to keep the compression up. Spend some time doing some good bowl work and port matching on your stock heads. Its not that hard to do and if your on a budget it can yield some good results if you take your time and do it correctly. A cheap summit or purpleshaft cam will make decent power if you cant spend much money. Buy the best torque converter you can afford