Originally Posted by 350RocketBoy
I have a 78 350 rocket that has 3a heads on it that I'm going to rebuild for the first time. I need to know what mods/parts i need that can get me close to 300 hp I have the engine in a 2 door 85 buick Lesabre with true dual flowmaster exhaust. The car is a daily driver but I dont want a rocket in my car thats a punk, so what can I do to beef it up from the top of the engine too the bottom of the engine
First thing to do is lose the 3A heads and get a set of #5, #6, or #7 heads from 68-71. Note, do not confuse these with the 5A and 7A heads used on the 80s vintage Olds 307s. Next, depending on the extent of your rebuild, you can get new pistons. Olds mainly varied compression by changing the size of the dish in the piston, however starting in the mid-1970s Olds also used larger chambers in the heads. The 5, 6, and 7 heads will have chambers about 64 CCs, vs about 80 CCs for the later heads. Have the W-31-size valves installed also (2.000 intake, 1.625 exhaust). Finally, select a good dual-pattern cam.