340 intake and carb combo
If you're taking the engine out anyway, take 40 lbs off the front end and pick up a few HP with a good aftermarket dual plane manifold and a Edelbrock AFB style carb, or even upgrade to an Edelbrock AVS2. My preference is an old Edelbrock LD340, but the newest Edelbrock dual plane manifolds are also excellent. A Weiand Stealth is also an excellent choice and can often be had for less cost.