If you look at the regulator on the inner fender, you will see another regulator which the fuel just runs thru. I tapped into the fitting there for my inside gauge thinking it would read pump pressure. Didn't see a problem doing it this way as if i ever go back to my Dominator, the regular is right there. I get it, with a return it will only have what ever pressure i set at carb.

I'd remove the regulator on the inner fender. Replace it with a union fitting and put the regulator back in a box on the shelf so if you go back to the Dominator you have it. Running two regulators in series like that is asking for problems. If you need a place to tap in for fuel pressure then use a union fitting with a 1/8 NPT port on the size.

Theoretically, should be at least double what you want at the carb to over come the G's on the launch....I am at around 20-22psi before the regulator, right off the pump last I looked.

Thinking it’s time to retire my old SX fuel pump. Looking at a Magnafuel 275 and a 300.

I've used and ran both of those pumps
If I was building a new car and needed a pump I would buy the 300 to start with
You and I both know we will want more power later so why not buy the bigger pump first
My new Drag car has a Magnafuel 500 pump in it, hoping for over 1000 HP N/A

Cab are you using that pump with a return line or dead headed?

Been running the Magna fuel 300 for many years and even on 1 plus hour drives and it's a great pump and no return needed, it returns directly back to the cell .......

Looks like a nice pump. Rated at 950hp, not sure how accurate the ratings are thou because my current SX 160 pump is rated to 1000hp. I read the manual for the MagnaFuel pump and says return can be at the pump or at the regulator. Looks promising any way.

I use the factory fittings on the pump to return to the tank, not from up front back to a stock tank or one with the tank, in the rear

Ok, but a couple things. Why do they make these return regulators if you can't return from the regulator? Other thing, the Magnafuel 300 says you can't run pump more than 1.5hrs at a time, whats up with that? I wouldn't normally, but never know.

I run 20 psi to my fuel log.

I have a Magnafuel 275 and have had issues with the seal on the shaft of the motor leaking. I had it mounted laying down so that may have an effect on it, although Magnafuels tech told me it could be mounted in any position. I got tired of replacing seals and took it off and put my old Holley Billet 150 back on.

I read a bunch on reviews on the Magnafuel 275 that were not positive. Many leaking pumps or locked up.

Magnafuel pumps are good pieces for sure and I have used them many times. If you can swing it look at the Weldon stuff. It is a much better product than Magnafuel but you pay for that. Since we switched I wont go back to MagnaFuel. Plus Weldons regulators are nicer and the low pressure one at the carb is a simple turn of a knob.
https://www.weldonracing.com/

I looked at their stuff and I agree. I have read all good about Weldon. Too pricey right now, think I’ll get the Magnafuel 300 ordered today. Thanks guys

I had a Magna 275 on my Duster, and had zero problems with it. Last year I switched up to a Magna 500 and had zero issues with that one. I was just too close to the limit I think on the 275 that it was time to update when a good used 500 came up I couldn't turn down. You have to have a good regulator with one of these....No cheap ones. Its a lot of pressure to hold back. My other fav is the A1000, I love those things. Great pump with great versatility.

I have a Magnafuel 500 pump a friend gave me, but it needs a rebuild. I orders the Magna 300. I think it will be plenty.

I have 18 psi at the pump and 6 at the carbs -8 to carbs with no psi drop at launch but i had some at 14psi. 1.40 60'

Mine locked up at the drag strip after about three years of street/strip use. I completely rebuilt it and after about six months it started leaking again so now it sits on the shelf. I'm not sure I'll ever use Magnafuel again. From what I understand the pumps are made here and the motors are made overseas.

Yep, i have often wondered why people spend all that money on those, which i always hear tales of woe about. When a Holley black will easily satisfy the needs of 95% of the N/A street strip or bracket cars on the board, and are way cheaper and very, very rarely fail.
I know they are plenty capable of supporting a high 9 sec 3350 pound car, using a T brake.
Most foolish thing i have done( among many..lol) was getting talked into “ upgrading” my fuel system. I did, and didnt see a thousandth difference, except in my wallet.