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Discussion Starter · #1 ·
I've never tuned a carb before. I'm mostly an EFI Guy and a Labtop, but as most of you know the new motor will be coming together (Well top end kit of course) 350 shotblock, LT4 cam Vortecs and an Airgap. I purchased a new Edelbrock 600 CFM a few months back and I dont feel like spending another 350 for the 750. Carcraft only made 4 more HP with the 750 vs the smaller carb + I dont plan on spinning it too high. About 5-5200 max. I assume the carb that comes from edelbrock is pretty good for a start. The motor now, 350 with a small crane cam and stock heads and intake runs perfect. Plugs show no signs of detonation, but theres no color to them. They literally look like I've just pulled them out of the ac delco box. All 8 of them. When I first put the carb on the mixture screws were messed up and the plugs were black after 15 minutes ideling back to the docks, but once I watched Edelbrocks DVD that came with the carb and how to adjust them. No black and no carbon line on the boat. No smoke, no smell or raw gas or anything. Runs super. To start should I keep the carb the way it is and relook at the plugs or change some stuff?
 

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your engine would be hard pressed to use more than the 600 (volumettric efficiency, cubic inches, rpms, etc..., 600 is plenty), and would likely lose some throttle response off idle in particular if you went with the edelbrock 750.

sounds like you've got it dialed in for nowand yes the jets, rods and springs that come installed should be pretty close and actualy shouldn't require more then a couple steps richer to meet your increased fuel requirements.
 

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easiest way to know what to change is to look at the chart in the edelbrock instructions for your carb and let the plugs and the way its running tell you what you need to change. You might be ok right where you are once you do the upgrades on your engine, or you may get away with changing metering rods a couple of steps richer. I would have the metering rods and jets (if needed) on hand to go two steps that way you can run it, see where you are and make adjustments in real time.
 

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Discussion Starter · #6 ·
Edelbrock makes a nice complete tuning kit fo rthe 1409 carb which includes all jets and rods possible for the setup. I was thinking of picking it up. Its about 40 bucks and comes with another DVD and a nice case to store everything.
 

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you can do that if you want to. I've got one and have added a number of rods, jets and springs to it over time. To be honest and since you're on a budget, etc... I think you're going to be fairly close to where you are now once you get finished putting your new heads and so forth on. You won't need the different springs, and at most will need one or two ests each of jets and metering rods. Might be smarter to just buy the ones you need... or if they're ones I have more than two sets of on hand, I'll send em to you if you like... Just a thought...
 
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