I would if you keep and want to throw a little more money at it is go with a down draft ITB. Check out foxinjection.com. That guy is a sweet heart to deal with and is such a big help. Check out his billet IDA ITB. they are bad ass. Sorry did not mean to make you spend money.lol
The down draft works fine. The manifolds back when i got mine was called the aussie manifold. I had a 13B 6 port street port running same as you. I had a 48 IDA bored to a 51 with external fuel bowls. Loud sum bitch.