Yes , great for a magnum head, and 'okay' for 2.0 intake valve. The exhaust you can sink a little on those and not hurt it so bad like with an LA exh port. I think in regards to flow and work invested...the 2.0 int hurt you because I'm thinking there isn't enough bowl and ssr work to take advantage of it. A 1.94 would actually do those numbers ...but I'm not scoping them out on the bench in front of me to see exactly where I'd do a little, not more than another hr across both banks, work to get that .300 into the 190's, it would bring the rest up and .500 flow would appear.
I don't think its the bench either, the super1020 usually shows higher numbers than my bench, by 4-7 cfm, ah but screw racing flow benches.lol The cam is small so to me the low lift is very important here with that sub .500 lift cam, .3-.400 lift matters more if the goal is optimistic. Thats my input relative to the heads and valve lift, not the entire build or idea of cheaply done and of course the casting may not be the greatest...but for what you're workin with , you're still doin good.
Im not a believer of magnum heads, did a few sets...but I won't waste my own time or dollar with them....now if that's what the customer wants , its their money...