i have 2 simple questions, relating to inlet manifolds.

1: are 12A and 13B manifolds interchangable?

2: to run an aftermarket carb, ie a weber or delloretto etc. is a custom inlet manifold required, or can u use the stock one?

 

1: If you have an adapter then yes.

2: The stock one will not work on the 12A cars. You'll need a new one. If you have a GSL-SE, you'll need a new upper manifold.