Honestly either could get you there, nothing wrong with a 402 (heads likely flow abit better on the 402), but I'd still say to use the 440. Summit 6401 cam (guys that have used them say they work good in low compression 440's), performer RPM or Holley Street Dominator would put you in the 350+ HP range. There are high flow exhaust manifolds but for probably the same price you could get some block hugger shorty headers that Hedman makes