i was curious i have a mechnical fuel pump would i have to switch to a electrical pump if i go with a nitrous plate setup for my carbed 355

How much of a shot do you plan on running? If your gonna keep the shot limited then you will be just fine with a high volume mechanical pump and regulator.

probly no more then a 100 shot. who makes a good high flow pump right now just running a stock one.

Any of the major manufacturers will work good. I personally run a 130 GPH holley mechanical with a holley adjustable regulator set at about 7.5 psi. I have ran a 175 shot with no problems at all and I plan on more. I normally only have it set on the 100 hp level though. I plan on putting on a big shot plate system and I think I will upgrade once I start really leaning on it (more then a 250 shot). You will be fine with a mech. one.

sweet. right now iam also running a 600 holley would need to upgrade the carb to something bigger or just change out the jets

The nitrous system comes with a nitrous and a fuel silonoid both of which will have to be jetted properly per spec on the system. U normally don't have to change the carburator jetting assuming you have a proper tune on it right now. You will have to tap into your fuel system for the fuel silonoid though.

cool thanks for the help