i have a 98 suburban that has a 5.7 vortech in it. i am going to have to rebuild the motor (i am wanting to build a 383) and was wanting to know if there is any way to upgrade the factory fuel injection or if there is an aftermarket intake that will adapt to the factory fuel system and cpu. i belive the intake might be warped and the fctory spider needs to be replaced

i am also wanting to put a towing/rv cam in it for more lowend torque.i am planing on putting bigger tires on it and i will be using it to pull my race car so i will be needing more lowend torque than anything.

i am very unfamiliar with this engine management system and do not know if any of these upgrades are evev possible.

thanks in advance

 

The factory PCM is capable of driving any standard high-impedance injectors. Any EFI intake manifold compatible with Vortec heads can be bolted into place, but you've got to decide what you're willing to give up and/or fabricate to make it work.

As you suspect, the factory injection has no options for increasing the capacity of the fuel injectors.

For replacement manifolds you have to take into consideration throttle-body compatibility, EGR, Evap purge solenoid, MAP sensor, coolant bypass, and coolant temp sensor.
-How much fabrication are you willing to do adapt the pedal and cruise linkage to a non-stock throttle body, throttle position sensor, and idle air control motor?
-Do you care about EGR?
-Do you care about Evap?
-Do you have an investment in a cold-air inudtion kit that you don't want to forfeit?
-Do you own TunerCat, EFI Live, or Jet Dynamic Spectrum Tuner so that you can adjust for the cam?
-The stock heads are limited to very low lift - this will limit cam selection but should be fine for low-RPM cam.
-Cam must be "factory roller cam" with stepped nose to be compatible.
-The front timing cover is disposable single-use. Some claim to have been able to re-seal it with RTV but better to replace.
-Align TDC and mark distributor rotor before removing. The #1 cause of Vortec 350 complications after this sort of thing is incorrect distributor reinstalltion.
-The biggst question of all is: "How much can you and do you want to spend?" This is not an inexpensive project.

Take a look at the GM Ramjet 350 intake manifold, Edelbrock, and GM L31 intake Manifold. None of them bolt up issuelessly and all three have trade-offs and compromises.

I can tell you for a fact that the factory intake manifold and injection will support an RV-cammed 383 as long as you tune for it.

 

Or you could do this and swap in a 6.0L!

http://hotrodlane.cc/PDFFILES/Lisa%20Tahoe.pdf