A few questions

You can try the milodon road race pan, holds 6 qt. I have one but give a shout to autoxcuda, pretty sure he can tell you if the pan will work with a /6 k frame. I'd go with aluminum heads, you can get more compression out of the motor that way. I just ordered a set of eddy 63cc heads for my 340. Should be here today. Also are you going to put a roller cam in it? If so I got a thread going about push rod angle, check it for thought.