Is it ok to go with bigger injectors then needed for possible increases later or is it possible to go to big. I probably only need 60s but want to know if i should get 80s. Thanks

 

umm....realistically how much HP are you gonna be running? do you know how big 80s are or even 60s for that matter?

really tho, dont even bother. you have zero reason to swap injectors. doing them now will put miles on the new ones for nothing. you can swap injectors but you need to get a tune, you cant just put them in and drive.

 

http://www.gtsparkplugs.com/InjectorSizeCalc.html

Use that.

 

^+1, two other points:

1. Injectors that are wildly oversize will be very difficult, if not impossible, to properly tune;
   
2. At 85% duty cycle 60lb/h injectors will support 680fwHP, 80lb/h units 900fwHP--unless you are planning very robust 4.6L build those are at and beyond what the 4.6 modular block can handle. The stock bottom end is only good to 420 or so.

 

80# Inejectors?? you plan on pushing 1000 hp?

 

The goal would be 650 rwhp. I have a built block with a d1sc procharger. I just wanted to make sure i am getting the correct size. I also have a nitrous kit but not sure i am going to use it.

 

I am running 400 hp now because of fuel limitation. I have been stock piling parts in my garage. I have the complete fuel system except injectors so i wanna make sure i was buying the correct size. I though 80s would cover anything but if its going to be a problem to tune i can do 60s.