Where can I get upgraded injectors for this intake and fuel rail?

ditto - need 55#

I've looked on Marren's site and also fiveomotorsport, but there seem to be to many variables and I can't seem to find any that measure up the same as my stock injectors

Call Marren. I got my 55# injectors from them last year for my modified 500EFI's.

Do you happen to know the part #?

I have a new set of 50 lb for the 502 magnum,got them from arizona speed,in box never used,there is 2 different sizes for the 502 mag if they are the right size i can make you a good deal on them,dave 410-956-5381

I have 2 sets of OEM from a pair of HP500EFIs. Removed when we installed superchargers. Not sure what size they are... They had about 150 hours on them and are from a 2000 500EFI. (worked fine when removed in 2004)

If they'll work for you, I make you a sweet deal...
Thanks, Curtis @ Billet Marine

Sounds like you have some to choose from. Marrin Fuel Injection is a very good source if you go new. Otherwise a used set is fine, spend the money to have new screens installed and get them flowed prior to install!!

Have no idea, I called them and the guy on the phone seemed very knowledgeable. They tested my old ones to determine some were bad and then matched the flow rates of the new ones before sending them to me. Since I bought new one from him they didn't even charge me for testing the old ones.

BTW: I shopped around a little before they were finished and he ended up being cheaper than anywhere else I found.

I was told the stock injectors are 42#.....verify before using.

Call fiveomotorsport. I got 65 lbs per hour injectors there. I am sure he can hook you up with 55's otherwise just go with 65's they will still work because they are high impedance and have a great flow pattern.