The plan is to run 10 PSI on a forged piston/rod 355 cid with the stock cam.
Can I leave the stock regulator?

 

yes
The stock regulator will maintain a 43.5psi difference between whatever it sees on the vacuum port and the fuel pressure.

 

Thanks for the reply.
What are you guys getting away with as far as the stock fuel system is
concerned, lines,filter,regulator,fuel rails.
Excluding a pump or pumps to support the power goals.

I what a high 10 sec DD.
About 500-550 RWHP should be enough.

 

You might want to read through the "High HP Fuel Systems - Q&A (4th Gen)" stickied on the Fuel and Ignition forum topic listing.

 

Still have mine supporting ~800rwhp.

Rich