This is one of the most easiest engines to build with any combo, from a 3.8 crank large bore to 4.5 crank small bore. Here's a combo that will get the hp you want 4.25 crank with 4.25 bore 6.385 rod cam 112to114 center around 270to280 dur and 600 to 650 lift and a set of dart heads alum or steel, brodix bb2 you can bolt these heads on right out of the box. The intake can be dart,eldbr,holley,brdx single plane with 850cfm carb. The parts should be port match as for the rest you know what you need to make it run. Remember you get what you pay for. Hope this helps. Good luck on your build one more thing balance the engine!!!!