Car is a 2005, 2.4, fp red with Kelford 272s.
My current fuel setup is 1200cc injector and a 255. Tuner said the 255 chokes right around 500 but the injectors would be enough.
Choices for more pump? He suggested going dual 255 with the second on a pressure switch. I really don't wanna spend that money if I don't have to. I'd rather grab 1 400 or 450 lph pump. He said they would be top much for stock fuel lines.
Any input? Thanks.

 

Sounds like, for sure, you are out of pump. I would consider using this pump kit which looks nicely set-up here:
The vendors notes here:


If anyone's interested, its $500 with your core, or $600 without your core.

http://www.tscomptuned.net/fuel-system.html

 

Rule of thumb is to not run the injectors over 80% duty cycle but many people do. A red should make 450ish on pump gas but 500 may be pushing the limits on that fuel. At least for me. I'd rather have better fuel if I'm going to push it.

If you are talking E85 then you don't have enough. 1200's aren't going to cut it If you are trying to make it to 8000rpm. 1300's are good for about 150hp a hole so 150x4=600hp . 600hp x 15% (drivetrain loss)=90hp 600-90=510whp

FWIW my Car on E80. Higher ethanol content will increase duty cycle.
A stock 255 with stock wiring was out for me at 430whp on my stock engine/red on 1300's
450 pump on stock wiring was out at 470whp on stock wiring.
450 with a boost a pump (increased voltage ) was out around 500whp.
Built 2.2
" " with 1700's makes around 600whp on E80 .

From what I've seen the larger engines choke (backpressure is higher if its a MHI housing) and fall after 7500 or so If the duty cycle is maxed with smaller injectors you could just limit the rpm. The 2.4 will come on earlier then a 2.2 if its tuned well and you still have a good powerband.

The Red is capable of making over 600whp , so If you want get 1650's/1700's you can achieve that.

I would run the 450 pump to avoid one of the two pumps getting weak one day and leaning out. There is a how to from Mfred on how to preserve the high/low voltage so that you don't overrun the stock FPR with the larger pump at high voltage.

Just my .02