Long rod 306??? 400 sbc crank and chevy rods.

[jonnyk]

Actually a long rod will help you more in the topend range. The longer dwell time at TDC promotes combustion when the piston speeds are much higher, so it's ideal for high revving engines. On the lowend it will actually hurt you because you're not taking advantage of the dwell time (engine is turning slow enough for efficient combustion), and the increased piston speed doesn't allow as much time for cylinder filling when the valves are open. IMO it's just hype, the gains or losses in either area will be minimal. Spend the money on something else.