Welcome to this forum! Boy, did you come to the right place! This is the best of the web in my opinion. There is alot of experience here and people are willing to share what they know to anyone who takes the time to ask.

I came here as a rebuild first timer , and would never have attempted my rebuild without the help I've been getting. I settled for a mild, torque favoring build but there's some doing creative agressive build ups too.

If your wanting to stay 351M your options are limited. Since it's a 400 block, most will advise building it as a 400, which is what it was engineered to be originally, and inherently yields the most power from this engine.

I know I haven't answered your question, but you've stepped into a world of experimenting enthusiasts who are still pushing the limits of this engine, and their properly verifying the results on the dyno too.

Sit back, more to come and hope you stick with this, it's been very rewarding for me.