Building up my 68 340

Ok guys. Took the heads off and the cylinders had some lines on them. Nothing bad at all but I figured while I had it out take it to the shop and get a hone and new rings and bearings. The cam looks brand new and we are gonna see what is in it.

I have read the dyno derby article and it said 392hp. Pretty much identical to what I plan to do. Have others had similar experience? I have decided I would really like to be close to 400hp if it is easily achievable while we have the motor apart. How much difference would a bigger cam add?

Fwiw I have decided to go with my original 904 transmission and before I buy a converter I need to make this decision.