Injector sizing
 

I recently wrapped up a head (CNC ported GM 243) and cam (228/232-112lsa) swap on a 2004 LQ4 that I've swapped into my 70 GMC and have been looking at swapping injectors. I've used several of the online calculators for sizing, but haven't come across any concrete information. I'm estimating my hp at the crank between 450-500. The direct swap route would be to swap in the 8.1L injectors that flow 36 lbs at 58psi. I could also swap the marine 8.1L injectors that flow 42 lbs at 58 psi. I've also been told I can swap injectors from an LS2 with new lower O-rings and different connectors. I'm still using the truck intake and fuel rails for now also. What are others using in similar situations? I'm open to any suggestions. Thanks!

Re: Injector sizing
 

8.1 injectors are a waste, unless you do locate the Marine 8.1's. In most cases, your better off swapping to either an EV1 or EV6 plug, and running something like an LS2 or SVO injector. The pigtails can be bought online, or snipped yourself from a wrecking yard.

Keep in mind the pressure rating on any flow info. SVO injectors are 39lbs, but at LS rail pressure its closer to 45.

Re: Injector sizing
 

A set of flex fuel truck injectors should be fine for what you're doing. Drop in, change tune and off you go.
Ebay has them for $100-150/set.