Which air gap manifold?

Thanks Guys,
I'd be happy running into the 13s. As the pic shows, I have no traction either. I'll be fitting a Suregrip and either 3.55/3.91 gears )just need the price of £Stirling to rally a bit!), I also now have some Drag Radials which should help get the traction down and lower my 2.37 60' marks