As long as you are feeding restriction free straight thru the regulator and then bleeding off the extra fuel back to the tank close to the rails you are fine, I converted my 502 mpi intake to twin rails a few years ago and made 1115 hp safely this way, sure the rails would get cooled a little bit more IF the fuel was traveling thru them BUT there was absolutely no room at the distributor to do this, motor has NEVER leaned out, vapor locked etc and has been ran at wot at 6200 quite a few times for minutes on end. As far as you feed size to the pump, it should be fine, are the fittings you talking 3/8 id or od? I ran the stock suction fittings on my 502 years ago at the same hp level you are trying for now and don't remember having supply restriction problems, I DID have problems trying to get the a1000 to keep up when boost referenced to 75 psi as its out put is cut about in half when raising the pressure, that pump becomes small around 700 hp or so when turned up high. Any blown application should have a fuel press gauge in the dash , I am sure you probably planned that already, good luck, Smitty

Thanks smitty, I had been reviewing some of your posts about going to the twin rail setup etc so I was hoping you would chime in. Also thanks for answering my question on the suction hose size. It's ONE 3/8" barb fitting attaching to the water separator at the factory fuel line which is 3/8" O.D. Which I think is 1/4" I.D.
Like I said after that it goes to the -8. I was going to do some machine work on on the water sep to open it up some.

If it we me, I wouldn't run anything smaller than -8 on the inlet side of things. I have a totally different setup, roots blower and mech pump, but I have -10 from tank to fuel separator. The separator is the big wix style filter, with 1/2 NPT in/out. Then after separator its -10 to the pump inlet, -8 to the 3/8 fuel rails on outlet side of pump. This setup supports my 800hp engines. I'd rather be larger on the inlet side. The pumps push better than they suck.

This is the filter head I run

http://www.cpperformance.com/p-13483...nd-outlet.aspx

This is the filter I run

http://www.cpperformance.com/p-13141...7-12-tall.aspx

I'd be sure to have a fuel pressure gauge on it at wot, or a AFR meter to make sure you don't go lean. It wont take long to melt the pistons.

I guess my biggest issue is not being to sure on how to easily remove the fuel tank in my baja then... My seats are bolted through part of the cover over the tank and you can't even reach the damn nuts on the bottom of them!

You don't need to remove the gas tank, if you are concerned about the suction line being marginal you can access the sending unit/suction line thru the small portal at back of center filler panel or remove the giant panel in center (My 272 has one, I assume the 25 does too?) to get to rear of the tank, unscrew the suction line,I remember mine having 3/8 pipe threads, once removed you can make a new thin wall suction tube and bore out the fitting, then silver braze the new suction line into the fitting and replumb with whatever you want, again, there are ALOT of procharged Bajas running the stock suction at the 650hplevel so I wouldn't lose sleep over it, as mentioned too a AFR gauge is a real good idea, at least a fuel pressure gauge. I just bought a pro-comp 2 5/8 analog AFR meter with o2 sensor for my turbo charged snowmobile and it was quite reasonable, Smitty

well if you feel like im ok with the stock suction hose feeding my setup then im going to stick with my original game plan and knock this ish out i have a turbo rzr to build next gotta get this finished!

What regulator do you have?

Please dont tell me stock....

No, first post stated all aero fuel system, its the marine bypass style boost regulator

I'm doing my fuel system for my blow through m3 right now and this is what I did :

Removed the check ball and 90° elbow from the tank. Installed a 3/8 npt to -10 in the tank, -10 braided hose to my aeromotive 100 micron fuel filter and a1000 pump, -10 from the pump to my monster marine water separator (1/2" inlet and outlets), -10 out of the water separator to my aeromotive regulator, -8 stainless hard line from the regular outlets to the carb bowls. My return is -8 from the regulator down to the fuel fill hose adaptor which is less than a foot away from the tank inlet....less chance of fuel working its way back up the fuel fill hose with it that close to the tank. Also, there are no elbows in my system. All the fittings are "full flow " an fittings.

I see, you only have 70+ post and you were not very specific on your application. No reason for any rudeness, from others.
You can fabricate a new pickup on the tank to -10 -1/2 npt, for the rest of your questions; I would contact Alex Haxby, or Eddie Young, either one of them has plenty of experience with the Prochargers.