Changing Carburetors...comparing advice

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UP of MI.
Jan 28, 2003
UP of Michigan
I'm running a Holley 750 right now and it's a little much for me. I've tuned it about as far down as I can and it still dumps too much fuel through. Not too mention the fact that I'd like a choke for winter cold starts and I haven't even looked to see if this one has a choke.

Leading to....electric or manual choke?

Also; I've been told to go with a 650 cfm. I don't climb hills, go vertical, or require a carb that can operate in a climate similar to Mars. So, for a practical purposes, what are your recommendations.

I'll take this advice to the dealer with me, so pour it on. Thanks.

Assuming we are talking a stock to mild 350 sbc the 650 is a good cfm-wise choice.
Ran a holley for 2 weeks....returned it
Ran a Carter for 7-8 years, spent a lot of time tweaking it to work halfways decent offroad....downgraded from a 750 to a 625 and that helped, still not perfect
Ran a Q-jet, $100 including rebushing the baseplate primaries, the gasket set, and the junkyard purchase....loved it until...

TBI baby... :flipoff2:

Give us some engine specs. My old 350 was .060 cast flattops, chromoly rings, balanced, 1.6 roller tips. .020 shaved heads, 2.02 exhaust, weiand dual plane, Accell HEI, 272 Comp Cam, advanced timing, peened rods, and more....$3500+ in that thing, and a 750 was really more than it needed...

flat tops...peened rods...weiand....common Woody this is some of what you need relieved domed pistons....polishied rods.....bwaaaaaaa

bored with digi camera
Running a stock 350 with headers and flow masters. (sorry, forgot that part).

It's just a little much on the gas is all. I've heard a 650 should suffice, but then the names flew out at me, then the applications, etc.

I live within pissing distance of the Gulf of Mexico, we have more sand here than Jenna Jameson's ass crack shooting beach porn, and I've got little to no interest in driving to Tennessee to wander the mountains. Don't get me wrong; minus business obligations, I'd love to remain in Upper Michigan and enjoy the outdoors more.

So; I'm at the mercy of the board. Which brand, and I suppose a 650 or 625.
Let 'er rip.

Thanks to all.

Edlebrock used to have a nice calculator spreadsheet you could download and determine flow needs for carbs based on your engine specs...haven't been able to find it tho....

Carter AFB is offroadable, and with their mechanical secondaries can be a real road screamer. I've got some mods teched up that help it out (see tech section). 625-650 is perfect IMO for your motor...might even get away with a 500 for 90% of your use.

If you want fuel mileage, Q-jet no question....tiny little cute primaries for driving, mongo vacuum secondaries for phat feet. ~750 in size, but their tiny primaries allow it to run on anything from a 305 to a 454.

I still vote a junkyard trip for a Q-jet...
The Q-jet Woody is making mention of is a nice choice with no downsides except a little harder to rebuild. Your other question was about choke ... I'd not recommend electric in a cold climate. The choke warms up and opens on its own whether the engine is ready or not. It's good for me here in NC but otherwise I'd do manual (or a heat riser).

For reference I'm using only a 600 (Edelbrock) on my 383 and very happy with its road manners and response. It breaths well until about 6500 RPM, plenty for my needs. If wanting 7500 RPM a 750 would be more in order.

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