In a few days I'm going to be ordering new injectors for my motor. Now I am at the dilemma of whether to go stock and order 19lb injectors or get the 22lb injectors instead.

My current setup is a 305TPI with the following mods (The one that matter anyways):

- New longblock bored to 310ci with 53cc heads.
- Edelbrock TES headers with flowmaster catback
- Accel HEI coil and wires w/ MSD cap & rotor
- Holley AFPR
- SLP runners w/ portmatched plenum
- Accel lingenfelter manifold base to be installed at time of injector swap
- MSD 6AL to be restored (PO removed it) due to lingenfelter manifold
- JET stage 2 chip (I know tuning is the best way to go, but for now until I buy all my PROM equipment I'll keep the measly 2* advance)
- All "free" mods including airfoil and K&N filters
(Also for what It's worth in the near future I plan on doing the 1.6 rocker upgrade)

Eventually guys, within the next 3 - 5 years I do plan on making a mighty mouse out of the 305 with heads, cam, valvetrain and likely a supercharger. For now, though it comes with everything listed above. I'm focusing on my 3.73 rear and paint/bodywork before I dive into the motor. It would not be beneath me to swap the injectors out again when the time comes for the motor mods, but if I can get away with 22lb injectors with my current setup I would rather do it once than twice.

I understand that tuning the PROM for 22lb injectors would run them perfect, but is it even necessary for the increased flow ability at the moment? Also, I read that some of the later year LB9's came with the higher flow injectors stock. Why?

I'm thinking for now that 19/lb injectors with the fuel pressure cranked up would be a much better choice with much less hassle involved, but I'll leave it up to the experts.

 

I'm running the 22 lb Bosch III's with AFPR and stock prom - no problems.

 

I would contact our site sponsor, Southbay Fuel Injectors. They will be very helpful for what you need and are super people to deal with. They were a big help with my upgrade.

 

I had talked to Southbay a few days ago, who said that the 22lb injectors "should" be fine.

I'm not looking for a ballpark conclusion though. I'm trying to figure out what will be better for my situation. 19lb with high fuel pressure or 22lb with low fuel pressure. I really should have posted this in the DIY PROM section...

 

even a 24lb will work the cpu modify s the injector pulse duration via the o2 sensor input to maintain the desired fuel/air ratio

 

I recently had to replace ours. I went with 22 lb. Part of my thinking was around increased ethanol use. My 91 was made when e10 came on the market. Next summer in GA we go to e15. Ethanol has far fewer Btu/gal than gasoline. Thus the greater Bledsoe will require more fuel to get the same energy in combustion. I assume the ECM will compensate for this. But if the injectors have a little more capacity it will be easier and provide more flexibility with higher ethanol blended fuels. Does this make sense? I will research more.

 

you can get an AFPR and lower the pressure if needed. leaner is meaner anyway.

 

when i ran 24lb inj on my 350,the ecm only corrected it to a point,still too rich,had to lower my fuel pressure about a pound.

 

Leaner is meaner? What?

 

i made much more power with the car running lean.

 

I'm not trying to be rude man, but from some of the posts you've made I can tell you have *alot* to learn.

 

rich wastes fuel,but it is easier on the motor