Is it actually in the low range? Normally HDL goes up the more you exercise (which I assume is not a problem for you).
Another thing to look at is your HDL to LDL ratio. Sometimes the ratio is more important than absolute numbers.
As far as healthy sources of fats, pecans are great, as are most other nuts. Just make sure you chew them well. Fatty (cold water) fish - make sure it's wild caught, not farmed. Or fish oil/krill oil. I think all plant based fats will be beneficial (avocados, dark chocolate (probably 80% dark or more), seeds, etc). As far as olive oil goes, best to incorporate it into your diet uncooked - hummus, salad dressing, garnish, etc. Or, if you do cook with it, do so on low heat. It tends to break down under high heat rather quickly, and the good fats in it break down.