If this is a street car I'd be using a TH400. TH350 is too weak.
If its a tall deck block with high rise manifold you're going to have some probs with the hood. In my 69 Camaro I had probs with the rocker cover hitting the brake booster. Chopped a piece out of the rocker and it was all good.
Highly recommend an electric water pump. CSR's are good.
Could be probs with the distributor and firewall too.