Other than weight, what is the advantage of having a aluminum dual plane intake for a 390?

If anyone needs any fe parts I have a complete 360 in a truck I am parting out. It has a 2 barrel intake. The engine only has 65000 original miles but it is locked up from sitting

I have a rebuilt 390 in my 79 bronco. I have the spark advance unhooked for the time being. I had a tank full of 93 octane gas and have the timing set at 11 degrees. The total timing is about 34 degrees. I was going down the interstate about 70  and stepped on the gas and it labor knocked like crazy. What is the deal. I was having trouble with this before that is why I unhooked the spark advance. I have a one wire dist and the engine has around 2000 miles on the rebuild by a machine shop. It has a small comp cam. If I slow the timing down any more it is sluggish

Now that I have 390 broken in or at least I think I do. I have driven it about 1200 miles. I am a little disappointed with the power. It has the comp cam 33-234-4. This engine does not want to pull as good down low as my old 390. It is bored 60 with stock heads and balanced. Why did my old worn out 390 seem to have more power. It was also bored 60 over stock heads with a rv type cam. The new engine has almost stopped burning oil but still has a slight smell of an old lawn mower that smokes. Maybe I just need to drive it some more miles. Also I have a hei dist. Can I do something it so it does not advance so much. I have it adjusted all the way out and am still getting some pinging at light throttle at highway speed. I set the timing again today to 34 total then test drove it it pinged a little at wide open throttle pulling a hill with the spark advance unplugged and plugged. So I backed off the timing 2 degrees but have not drove it yet.

I got my 390 back from the machine shop today. It is bored 60 with some exhaust work on the heads. It has a comp cam part number 33-234-4. The shop said it was built for torque. I also had it balanced with stronger rod bolts and valve springs. What kind of horsepower and torque should it make. It has the stock 4 barrel intake and stock heads with the exhaust work

I am thinking about having my 390 rebuilt by a machine shop that built it over 20 years ago. My question is about the gas mileage. When it was first done I could get around 12 miles per gallon. I am wanting more horse power so he is going to port and polish the heads, balance the lower end and put some kind of cam in it. Is this going to kill the gas mileage. He said it would make around 350 horse. I know is will depend on what cam but just dont want it to get 4 miles per gallon

I installed a hei distributor in my 390 with new plugs and wires a couple of months ago. The first thing I noticed was my mileage went from 8 to 11. I was surprised but happy. This was driving in town. Now I am back down to 8-9. What is different. I can not get any better than 8-9 now no matter what I do. How was it up to 11 for a few tanks right after all the new stuff?