Difference between a high pressure and low...

I was looking at Walbro 255 fuel pumps and I saw a regular 255 and a High pressure 255, for what reason would you go w/ the high pressure over the low?

Regular 255
http://www.extremepsi.com/store/customer/product.php?productid=17196&cat=560&page=1


High pressure one
http://www.extremepsi.com/store/customer/product.php?productid=16271&cat=430&page=1

Its like a 10% flow IIRC. Check the fuel pumps and injectors calculation sheet in the Tech article section for more info.

I dont think its going to matter, not unless you are looking for like 600+ hp.

But could you damage anything by having the higher pressure, such as injectors if you don't upgrade them?

the difference is just the pressure relief valve's pressure limit. No harm..