[liftlawssuck]

I have had the opportunity to reinstall about 4 of them now. Yes reinstall after the owners couldn't get them to run good. All of them had the same in common. All were GM cars running HEI ignition. The 1st was the learning curve for me. Many talks with Holley and figured it out.

The first I found was the wiring on all the installs were horrible at best. Anything with an ECM needs to be the best wiring you can do. Clean dedicated power and grounds.

The 2nd was EMI being induced into the ECM in the throttle body. I stuck some tin foil between the HEI and throttle body and all problems went away. So I took all the wiring off again and wrapped them with shielding.

You can't have exhaust leaks either as it will throw the O2 sensor off.

After all this the test drive went great with fine tuning the whole time. All the cars run great with no issues in the 4 years or so they've been on.

If you put these on a motor with distributor in the front the EMI isn't an issue. Or at least as much an issue.

Are they the best? No I don't think so. Do they work? Yes and they wake the motor up like never before. Do they have problems? No question of that. They have problems but Holley has always been great to work with. Would I put one on anything I have? No I wouldn't. I can't see spending the money myself. I'd rather do an LS swap if I wanted fuel injection.

Hope this helps!!