2011SVT 10 Report post Posted April 7, 2014 While I am waiting for the new engine to be built, I've undertaken a number of smaller things to make the car more drivable in the short term. Currently I have a stock-ish 428CJ build with about 1,000 miles on the rebuild. The only non-stock parts are the MSD ignition system (I just installed and it cleared up a number of problems) and a Comp Cam 268H that was done as part of the restore/rebuild that pre-dates my ownership. The carb is a period correct 730cfm Holley. My issue is that I believe the car runs way too rich. Reading the plugs plus the nice black exhaust seem to support this. I'd like to get in there and start monkeying but.... I'd like to preserve the 730 as it sits. I'd actually like drain it, wrap it up, and put it on the shelf for the next guy who wants to put everything back that I 'broke' :) So what should I get as a replacement? Ideally I'd like to get something easy to tune (without spending money on an EFI setup - just to forestall you well intentioned guys that point out a laptop is easier than jet changes :). Got an EFI system coming on the new motor). Thoughts? Thanks! - Chuck Quote Share this post Link to post Share on other sites
69gmachine 15 Report post Posted April 7, 2014 The original Ford Holley with annular primaries is an awesome carb when properly tuned. I would try to find out what's wrong before replacing it. I'm running one on my 408 and it is perfectly matched to my engine. I get great gas mileage (relatively speaking of course) and mine doesn't run rich at all. All the plugs look nice every time I've checked. There is a ton of information on tuning a 4150 style Holley on the interweb. Quote Share this post Link to post Share on other sites
DarkBuddha 107 Report post Posted April 7, 2014 Quick Fuel Slayer 750. It's the same design as Holley, takes Holley Jets on the primaries and has a tunable secondary plate as well, plus tunable vac secondaries. Plus it's only $300, so it won't break the bank. BTW, it was also rated the best "out of the box" carb in a Car Craft shootout: http://www.carcraft.com/techarticles/ccrp_1210_seven_budget_carburetors_tested/ Quote Share this post Link to post Share on other sites
70Mach03 12 Report post Posted April 7, 2014 You tried replacing the jets on your stock carb? It should be a 735 CFM Holley. I'm using a Holley Street Avenger 670 CFM on my 351C-4V in my 1970 Mach 1. It came a little lean and I went up a few jet sizes. I kind of wish I had gone with a Street Avenger 770 CFM as I've got a stick and could go a little higher. A 770 CFM is what I'd go with on a 428 CJ. http://www.holley.com/0-80770.asp Quote Share this post Link to post Share on other sites
2011SVT 10 Report post Posted April 7, 2014 I guess part of it is that I want to have a carburetor that is basically working, (albeit rich) to put on the side and then have one to 'play with'. If I muck it up beyond helping I can put the 735 back on and be no worse off :) I'd also like to find something with quick change jetting. Looks like the idle mixture and even the accelerator pumps are easy to work with. The jets and power valve are still a matter of pulling off the fuel bowls and metering block to change jets? Quote Share this post Link to post Share on other sites
DarkBuddha 107 Report post Posted April 8, 2014 There are models with quick change jets, but they're pricier. Quote Share this post Link to post Share on other sites
2011SVT 10 Report post Posted April 8, 2014 Do electric chokes clear the bottom of the shaker air cleaner assembly? Quote Share this post Link to post Share on other sites
70Mach03 12 Report post Posted April 8, 2014 Do electric chokes clear the bottom of the shaker air cleaner assembly? It does on my 351C-4V Shaker and should be the same on a 428 I would think. Changing the jets in a Holley is pretty easy, just make sure you have a towel underneath the bowl to catch the fuel. The factory jets in my old 1970 428 SCJ's 735 CFM Holley from years ago were .079's front and .099's in the back. My 670 CFM Street Avenger came with something in the low .060's. I keep bumping them up and I think ended up around .073's in the front. Quote Share this post Link to post Share on other sites
2011SVT 10 Report post Posted April 9, 2014 Ok, I went with a Holley 4160 750 cfm vac secondaries and electric choke. If I need to mess with the secondary jetting I reckon I can get a metering block conversion for another $40 but I doubt that will be necessary. Assuming the 4160 works well, then I can start work on the 735 and see if I get it tuned better than the new carb. :) Will keep you guys posted. Thanks for the help (as always). Quote Share this post Link to post Share on other sites
Chris'69Mach 23 Report post Posted April 10, 2014 You tried replacing the jets on your stock carb? It should be a 735 CFM Holley. I'm using a Holley Street Avenger 670 CFM on my 351C-4V in my 1970 Mach 1. It came a little lean and I went up a few jet sizes. I kind of wish I had gone with a Street Avenger 770 CFM as I've got a stick and could go a little higher. A 770 CFM is what I'd go with on a 428 CJ. http://www.holley.com/0-80770.asp I have the 770 Holley Street Avenger w/vacuum secondary on my 351C and it runs excellent!! :thumbup: Quote Share this post Link to post Share on other sites
70Mach03 12 Report post Posted April 10, 2014 I have the 770 Holley Street Avenger w/vacuum secondary on my 351C and it runs excellent!! :thumbup: You don't have to rub it in. :pinch: Yeah I wish I had gone bigger. :smile: Quote Share this post Link to post Share on other sites
