when trying to find a set of heads for a mild 289 street driven car. whats the best way to find out with specs to get? im looking at all the Volumes and sizes and dont even know where to start. any suggestions or know of any good online literature to read? thanks
Get flow charts. Look at the peak flow and valve lift that it occurs. For a good street motor, you want a lot of area under the curve. Flow should make good increases from .200" on up. What lift cam are you running? I don't think you could go wrong with 165 AFR's or Edelbrock Performers.
Velocity isn't shown but the smaller ports will have faster velocity. The bigger ports will flow up to .600" which you don't need. The exhaust is pretty much even.