Hi. Does anyone have any experience running a Fitech 30061-FR dual quad throttle body EFI on a 472 hemi? If so did you have any trouble with tuning or popping? The kit sells for about $1,350 on their webpage so the price is appealing. It also looks like minimal mods will need to be made (O2 sensor, fuel pump, minor wiring). I have two 4160 carburetors on a stage v intake manifold. It runs great but has always been a bit rich and tricky to dial into perfection. My main motivation for EFI is to prevent the fuel from boiling over when I park the car. It makes my garage smell like gas for hours and is hard to start. Do throttle body EFI's have that problem too, and do I need to go with a Edelbrock Pro Flo 4 port injection kit with a dry intake manifold to fix that? I like the Edelbrock kit but it's likely 3-4x the cost to complete the install (need to buy a different chrome air cleaner with the factory spacing) and my engine would look a bit less stock with the fuel rails.

If you are using a electric fuel pump only you can shut it off and let the motor idle until it dies to drain the carbs, I use to do that on my drag cars after bringing them home from the races so the gas wouldn't gunk up the carbs when sitting and evaporating between race weekends in SO CA Mojave Desert
Turn the electric pump on until it slowed down, pump the throttle twice and go drive it onto the truck or into the trailer

I'm waiting on the Pro Flo 4. Yes, it's expensive but it's very complete.

That's a slick idea, thanks Cab_Burge! Has anyone tried the Fitech?

If the holleys are boiling over I'm going to say the issue is with the carbs, fuel, fuel pressure or excessive heat. Edelbrocks have a known heat issue but never heard of one on a holley unless there was an issue. Ethanol based fuels will aggravate the issue.
Start with you float levels to make sure they're not too high.
I not too long ago had 2 brand new 750 vacuum secondary Holleys that would leak down internally. I actually took the carbs off, filled the bowls with dyed fuel setting on 2x4's with paper towels under them. Next morning id had dyed paper towels. I swapped them for quick fuel carbs and no further issue.
myself, i'm not too fond of the aftermarket EFi systems as I've had a few customers with older systems that no longer had tech support.

Thanks TJP. The carburetors are about 14 years old. It could be time for a rebuild. I did set the floats and tweaked the carburetors as best as I could. I never could get them perfect at idle (too rich) but they run great otherwise.

Try making sure the throttle blades are not open enough to be on the transition circuit on both shafts, remove the carb without touching anything other than the bolts or nuts holding it on the intake and disconnect the fuel feed and see where the throttle blades are in relation to the rectangular transfer slots
If they, throttle blades, either front or both, are open far enough to be showing any part of the transfer slots close them up so they don't and then try adjusting the idle mixture screws in so they are open one full turn each and see if idles cleaner If it is still rich slowly screw each idle mixture screw in until the motor idle speed starts to slow down a tiny (50 to 100 RPM :scope) bit and then adjust the other ones the same way and try that IHTHs

Thanks Cab_Burge. I haven't tinkered with them in about 12 years. I remember doing all the basics and wasn't able to get to where I wanted to be with the 4160s. They were missing something for adjustment. At one point I bought modified center bodies with removable jets near the venturi and had the choke towers milled off. The first install didn't go well and I put them in storage before I used them. I will have to take them out of storage and try again.

Feel free to correct me Cab, but I have always read that up to ~ .020 of the transfer slot could be exposed at idle with no ill effects.
One of the tricks recommended if the primary side is open too far due to a lumpy cam. tight converter, is to open the secondary side a bit or drill holes in the primary side blades (start small and increase as needed) to allow more air in. Both in turn allows the primary side idle screw to be backed out and returning to the idle circuit

Lots of misinformation stated in many places by folks who do that and don't realize that their carb should idle on the idle circuits alone, me being one of them years ago
The transfer slot is part of the fuel enrichment circuit to prevent a lean stumble or backfire when driving with real light part throttle low speed applications like in parking lots, backing up and so on

So all the books and theses images are wrong ? GOOGLE HOLLEY TRANSFER SLOTS IMAGES
AS well as the following demon / holley setup. make sure to read to the last page or two

From Holleys website on Demon setup

Some follow and believe, others don't