67' 300 440 Carb upgrade....
- Thread starter Cortez
- Start date
Stock CFM is approx. 600, which is all that's really needed. The new Edelbrock AVS-2 is probably still on sale at Summit for about $350.00 new. There are a few Holley numbers for the older vehicles, but they are probably a good $100.00 more. And there's also the Edelbrock AFB.
Considering where the accel pump diaphragm is on the Holley 4bbls, that might be one reason to go to the Edelbrock carbs. Or the 650cfm Street Demon.
Basically, 600-650 cfm, electric choke, and whatever throttle linkage add-ons needed to make everything work.
What's the problem with the current Holley? Just curious. IF you like your current OEM Holley, you'll not gain much with a new Holley, except new pieces. So you might seek to replace the throttle body and use a Holley kit (with the OEM thick base gasket!), and save your money.
CBODY67
Considering where the accel pump diaphragm is on the Holley 4bbls, that might be one reason to go to the Edelbrock carbs. Or the 650cfm Street Demon.
Basically, 600-650 cfm, electric choke, and whatever throttle linkage add-ons needed to make everything work.
What's the problem with the current Holley? Just curious. IF you like your current OEM Holley, you'll not gain much with a new Holley, except new pieces. So you might seek to replace the throttle body and use a Holley kit (with the OEM thick base gasket!), and save your money.
CBODY67
The metal line that the hose comes out of leaks terribly I was going to have it rebuilt and the fella said it'd be best to replace the whole thing...
By observation, some mechanics have been afraid of rebuilding Holley 4bbls for decades. In reality, they're pretty simple and no worse than anything else out there. AND, if you go direct to Holley, you can buy many of the needed parts to do that, outside of a rebuild kit.
"Leaks" were usually an issue with the older gaskets, but the new ones are much better in both reliability and durability.
I'm not sure about the location of your leaks. The only "hose" I can think of goes to the chock vacuum pull-off. Everything else is gasketed or has an o-ring seal. The other hoses (ported vacuum to the distributor and the vacuum line for the pcv system are on the front of the carb base.
The ONE emerging issue with Holley 4bbls is that the accel pump diaphragm is at the bottom of the primary float bowl, which gives it direct access to the fuel in the float bowl whether the engine is running or not. That means that with the issues of ethanol'd gas drying out rubber parts (from continued exposure to it), they will fail eventually. In this case, it'll empty the float bowl fuel onto the intake manifold, which is not good. The newer ones can resist it better, but in occasional-use vehicles, where the rubber might get dried out from no fuel in the float bowl, the diaphragm can become brittle and fail. They can fail with long-term use, too, but not nearly as quickly. But in a vehicle that sees somewhat constant use, less of an issue and they won't fail all at once, usually leaking first. Holley might have some improved diaphrams by now, too?
It's always nice to "go new", but all things considered, even the best aftermarket carbs are now "will fit" rather than OEM fit . . . AND there is a difference. Not just in OEM-spec fuel metering curves on the OEM item, but how the throttle linkage will hook-up. Most have a combination of the "Chevy" linkage (which is similar to the Chrysler hookup, but with some differences) plus the provision for the Ford kick-down linkage. Nothing major, but some additional items might need to be purchased/adapted to the aftermarket carb. On the '67 Chrysler, the kickdown linkage might need to be adjusted, but the key thing is to see if the linkage slips into the carb linkage FIRST. Adding one or two additional turns of preload will also raise the part-throttle shift points a few mph, which is good. More acceleration with less throttle input. NO durability issues, either, as I've done that on Chryslers I own and drive myself. My observations and experiences, others' might vary.
ALL that being said, rebuilding you existing Holley and replacing what might need replacement is still hundreds less than a "replacement" Holley 4160. Look at the online catalog, so you'll know about what's in there and can possibly discover what's causing "the leak". LOTS of stuff in there!
Please advise which "hose and tube" are leaking.
CBODY67
"Leaks" were usually an issue with the older gaskets, but the new ones are much better in both reliability and durability.
I'm not sure about the location of your leaks. The only "hose" I can think of goes to the chock vacuum pull-off. Everything else is gasketed or has an o-ring seal. The other hoses (ported vacuum to the distributor and the vacuum line for the pcv system are on the front of the carb base.
The ONE emerging issue with Holley 4bbls is that the accel pump diaphragm is at the bottom of the primary float bowl, which gives it direct access to the fuel in the float bowl whether the engine is running or not. That means that with the issues of ethanol'd gas drying out rubber parts (from continued exposure to it), they will fail eventually. In this case, it'll empty the float bowl fuel onto the intake manifold, which is not good. The newer ones can resist it better, but in occasional-use vehicles, where the rubber might get dried out from no fuel in the float bowl, the diaphragm can become brittle and fail. They can fail with long-term use, too, but not nearly as quickly. But in a vehicle that sees somewhat constant use, less of an issue and they won't fail all at once, usually leaking first. Holley might have some improved diaphrams by now, too?
It's always nice to "go new", but all things considered, even the best aftermarket carbs are now "will fit" rather than OEM fit . . . AND there is a difference. Not just in OEM-spec fuel metering curves on the OEM item, but how the throttle linkage will hook-up. Most have a combination of the "Chevy" linkage (which is similar to the Chrysler hookup, but with some differences) plus the provision for the Ford kick-down linkage. Nothing major, but some additional items might need to be purchased/adapted to the aftermarket carb. On the '67 Chrysler, the kickdown linkage might need to be adjusted, but the key thing is to see if the linkage slips into the carb linkage FIRST. Adding one or two additional turns of preload will also raise the part-throttle shift points a few mph, which is good. More acceleration with less throttle input. NO durability issues, either, as I've done that on Chryslers I own and drive myself. My observations and experiences, others' might vary.
ALL that being said, rebuilding you existing Holley and replacing what might need replacement is still hundreds less than a "replacement" Holley 4160. Look at the online catalog, so you'll know about what's in there and can possibly discover what's causing "the leak". LOTS of stuff in there!
Please advise which "hose and tube" are leaking.
CBODY67
70bigblockdodge
Old Man with a Hat
Those old OE Holley's are terrible and too many gorillas have tightened them down and warped everything. Its a shelf item to continue with the car in the trunk. Buy a new Eddy in the 600+ range new AVS2, my choice
The Goose
Senior Member
CBODY67 is totally right. My Holley just picked up the drips a few months ago. It was on my shelf for a while before I threw it on and in about 13 months of California gas the diaphragm failed. I went to the local corner parts figuring I'd have to order one. The "performance center" section (total joke but at least they're trying), had about 8 on the hook. Real Holley parts too. Didn't look any different but so far so good.
Another thing to consider is a rebuild guy. Not a shop mind you but a real carb guy. We have one in Palmdale and this guy has thousands of parts carbs and goes thru a carb with a warranty for about 170 bucks. Shoot a good kit runs $40 any more. Look for one in your area, you'll know if it's real when you walk in...
Another thing to consider is a rebuild guy. Not a shop mind you but a real carb guy. We have one in Palmdale and this guy has thousands of parts carbs and goes thru a carb with a warranty for about 170 bucks. Shoot a good kit runs $40 any more. Look for one in your area, you'll know if it's real when you walk in...
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