Not, true, the Holley system can do it. The sensor does not come with the kit.

I have been using the Holley MPI system for about 7 years. It starts better, quicker, faster and better fuel economy. If you make changes to the engine you get out the laptop and retune. No need to change jets or carbs. Be sure you get the wideband O2 option, much better than narrowband. I use the DUI distritutor with electronic control. The timing, fuel maps, startup, accelaration, ect... are all adjustable. No soot on the transom and no exhaust fumes from the exhaust when you start it up. They are expensive, I have about 4k in mine with wideband, upgraded 42lb injectors and AN hoses and fittings. I have seen the kits in CP performance, Eddie Young also deals in Holley, I am sure he could help you out.

I just switched to EFI from carb. No more pumming the throttle to start these. Just turn the key and let the computer take over. I am making 685HP and 720LBS of TQ with my 604CI EFI set up. I also have one extra computer in you need one.
Ken

Is there a big difference between the throttle body or multi port? The one is a small block chevy and 2 are bbc. I have seen a big price difference for sure.

Fuel economy is achieved with timing curve and fuel curve, EFI systems will set them correctly if a Wide band o2 sensor is used same is true for a carb if you know how to tune them according to what the o2 is telling you , but an ignition system that will simulate vacuum advance with the use of a map sensor is needed for best economy. The carb has to have adjustable air bleeds and power valve restrictor channels among other things. The idle circuits are always to rich and the high speed bleeds to lean causing an impossible tuning solution with the main jet. This is why most boat run fine at wide open throttle and suck every where else yes efis also, I've seen plenty of 1075s huffing black smoke at idle and pipes black as the ace of spades and owners wonder why the oil smells like gasoline and so on. So if Holley's efi system uses the same calibration as their carbs plan on putting the tech line on your speed dial. I'd save your guys some money and just get a portable wideband o2 unit so you know what the engines really want to run correctly. If you choose to go efi get a sophisticated system that does everything for you. big$$$

Funny my Blowen 600 with carbs do the same thing?

It is possible to get a bit more torque from Port injection due to injector timing. It is more expensive though.

Jeff

My Innovation Marine 500EFI uses the Holley system(with MEFI) and I get far better gas mileage at cruise than my friend's with carbed 330hp 454s.

I've seen good and bad from both....lots of factory EFI boats soot the transom up bad..run weird at certain RPMs, some work great no issues...but have had carb boats run great thru out and do well on fuel...so ???? getting it dialed in is the key...now just figure out which is easier..

You might look at the Fast, EZ tune and XFI 2.0 with self tune. http://www.fuelairspark.com/