You can use them in a car, but I recommend you block the water/heat cross over though.
Use .019-.021 thick steel and copper rtv.
Otherwise water will flow through the manifold. Some who have egr ,its a must or your motor will eat coolant... but non egr is no worries. But the trick is too plug them, pipe plug on the block side would be nice.
The exhaust ports are blind due to the water heated deal and so they all flow even with no end gas passed around to the other bank...which is why they're the most desirable 318 closed chamber head imo.
