im doing a build up on my 305tpi and was wondering if 19 lb. injectors would be ok for my combo. ported stock heads, ported intake , bigger runners, headers and exhaust, crane compucam 210/216 440/454. , upgraded ignition, and all the other little bolt ons and tricks. also will the stock fuel pump handle this. if the 19's are fine then i'm curious why the 350's came with bigger injectors.

 

Scan it and see the duty cycle when it's back together. I'd guess you will be ok as far as injectors go, but close to max. It all depends on how much air your motor can ingest.

 

they should be plenty for now,diff.heads bigger cam then i would say move up to 22lb inj. but they should be enough for now,do you have an adj.fuel reg....

 

thanks for the reply's. my main reason for asking is i have a friend that works for acell and can get me any size injector i want. so what i should be asking is what size injector for my combo above. 19,22,24 lb. injectors.

 

22 or 24's and get a chip burned for the size injectors you settle on.

The reason the 350's used 22# when a 19# set "could" support the engine is safety margin. The 19's could do it, but their life would be shorter because they will be working harder (pulsed longer)

 

With the 19#/hr injectors wide open (100% duty cycle) you could make 300HP at the flywheel. However, the injectors wont last long at 100% duty cycle.

You could make 240HP at 80% duty cycle and the injectors would last a long time.