Originally Posted by
Six_Shooter
I've never understood this "horsepower limitation" of an ECM. Especially when there are many people that have gone beyond the theoretical "horsepower limitations" of the ECM they are using. I've seen the argument that they are unable to control an injector large enough to support XX HP, which I have yet to see in any application. I've seen other arguments that were based on measured (or calculated) air flow, that again is not a limitation of the ECM itself... The technology used in that ECM is a different story, and that may limit what the ECM can control, but is not directly relateable to a HP rating.
If you have two throttle bodies I would strongly suggest using two IACs. The distribution of air will be more even across all cylinders. Crossfire systems use dual IACs, for this very reason. Dual IACs will also function fine attached to a '7427 PCM.
I would just move over to GM throttle bodies, getting away from the Holley injectors that are known for issues, and giving you the ability to easily add the IACs.
You can run each pair of injectors in series when using the Delco ECM. This is what has been done to my friend's '71 Cutlass with a custom 4bbl TBI, and his girlfriend's Olds powered '89 Caprice. These cars get driven and BEATEN on regularly. They are using the '7060 PCM however, but the injector drivers are the same as the '7427.