i was searching around here and noticed some people putting throttle body's and injectors from a 302 on a str8 six (i relize the plenum needs to get ported to match size for best performance) what will this do for my 87 bronco (fuel injected i6 4x4) Gas mileage? worse? better? how much? and horsepower more? less? and how much if any?
and will anyone of these be better by themselves for improving gas mileage?

 

I don't know what it will do but I doubt it would increase mileage at all.

 

i will probably do nothing except make you think you get beter mileage.

do it if it makes you happy.

 

Without improving head flow not much. You'll find the common theme for unlocking performance in these engines is improvement to the heads airflow.

Injectors are a different matter, sort of. If your not altering the fueling maps in the computer when you go to a #19 injector then you have to dial the fuel pressure down so that they function near the same delivery rate as the the stock #14 injectors. Several around here have stated that they are getting better throttle response with this change, from my point of view the jury is still out.

 

which motor has the #14 injectors?

 

#14 is stock for EFI 4.9/300. But...instead of operating at 40psi your ragulated to 60psi which has them operating as #17 injectors. If you jump to the #19 injectors without dialing the fuel pressure down you'll be over fueling (running excessively rich) because they will be operating as #23 injectors and the computer, with stock tables, would be able to adiquitely compensate.

The higher pressure is do to a tendency for the injectors to vapor lock at 40psi. This is caused by the extra heat that our intakes receive from the exaust manafolds.