I noticed I put "Barley"

Good luck getting anywhere close to 350hp with the gt40 heads, to do this you better plan on a giant cam, lots of compression and spinning up right to the point where everything wants to fly apart (and it probably will). Also you will lose all of and more of the drive-ability that fuel injection offers.

If money is an issue and you want to keep the "nostalgic look" go with a carb and use the other $400 to build a decent looking dash.