Intake/Carb recomendations

[adjudimo]

Happy Holidays fellow members. I would like your opinions to help me decide which carb and intake I need to purchase. I have a 1967 SS-RS 396/325hp with T400 automatic transmission and 12 bolt with 4:10 ring and pinion.  The motor is a 1968 396 out of a Chevelle. Currently the only mods that I know of to the engine is headers looks like 1 3/4" tubes ( don't know the brand ), Delco hei distributor and 2 1/4" flowmaster exhaust. The engine has the standard cast iron intake and iron heads and the current carb is a 1998 Holley 0-7002-1 model 4175 with 650cfm. I haven't needed to pull the valve covers or oil pan off and I guess that the internals are probably stock components. Sounds like it has a slight  cam when cold and first started, but mellows out when reaching operating temp. I have been having trouble with the engine stalling or quitting while actually driving it. Will not start until it sits for a bit. Then it does the same thing again. Due to other circumstances I haven't had the chance to work on the car and now the weather isn't fit to take a chance on driving it. The car has the SS hood and I know that I have to keep with a set up that will work with the clearance issues of the hood and the air cleaner. Even with the system currently on the engine, it has managed to cut into the hood insulation. I have a open air filter and it measures 3 inches tall, not including the extra 1/2 inch that bows up toward the center. The car is always hard to start and takes a while before it will idle on it's own. I went out to the garage yesterday and poured a little gas into the carb and it started right up. After running a bit I noticed gas leaking from the front of the carb onto the intake manifold, so I figured this is a good time to change things out. I really don't plan on doing anything else to the motor at this time, but eventually hope to get a overdrive transmission and switch out the rear gears to something in the 3:40's 3:50's or 3:73. And before I forget, I rewired the entire car with American Autowire Classic update about two years ago and have new plugs and plug wires. Everything works like it should. I don't think my problem is electrical.  Hope you can jump in with suggestions for the best intake/carb set up. I have been looking at Holley and Elderbrock, but just need the extra input from you guys/gals. Thanks

J.R.

[janobyte]

Did the car run good at one time and now displays symptoms ?  Start of cheap and rebuild the carb. I strongly suggest the newer style neoprene metering block gaskets. And fresh plugs. If the car was running poorly might have fouled/glazed a few. Throwing on bolt ons could be a mistake if you do not know the engines demands. By your choice of rear gears sounds like your not pursuing a stump puller but a nice cruiser with a rumble.
Check choke adjustment.

Try a low profile air cleaner for clearance issues---I think the first gen designs are hard to beat---

If problems persist post some pics of your problem areas.

[hotrod68]

  Sounds like you may have something in the needle & seat--Holleys are notorious for flooding if the gas isn't absolutely clean. I'd get a rebuild kit and go through the carburetor and put a good inline filter in the gas line. I certainly wouldn't trash it. As for the air cleaner, does your have the low-profile base? A factory-style open element air cleaner will drop the height a good inch. The Edelbrock Performer would be a good choice of intake with a mild cam. Sounds to me like it's just flooding a little at idle. New needles & seats will fix that in a jiffy. God luck and I hope this helps.
 

[Mike S]

  When all is done and you are back running again, don't overlook the fact that gas contains up to 10% ethanol. This can and does attract moisture and can lead to corrosion in the fuel delivery system even past the filter. I've repaired too many carbs on smaller engines (snow blowers, ride on mowers and even old cars) that have fuel filters and yet the fuel bowl develops a sugar/sand like corrosion that can lead to jamming the fine holes in the carb body and also leads to carb flooding due to leaky needle/seats leading to high bowl levels.

 There are several fuel additives to combat this problem especially in our hobby where a car can sit for a length of time. I recently read that the ethanol levels may be reduced if the EPA gets it way but there is bound to be a fight from the farmers who produce the corn crops and their representatives in DC so don't expect that anytime soon.

Mike

[hotrod68]

Good point, Mike. I had a couple of leaf blower and chainsaw carburetors get trashed from ethanol. I use Sea Foam in the gas now. It's inexpensive and seems to work.

[adjudimo]

Thanks for the replies. I plan to take the carb off within the next couple days. I really do need to install a inline filter. Only filter present is the brass looking filter in the carb. The car ran fine year before last and started acting up this past spring. I actually may have caused some of this because I didn't top off the gas tank like I normally do. I did however add fuel additive/ treatment. I have been on the Holley site and can't seem to pull up anything for a 4175 carb for a rebuild kit. I even typed in 0-7002-1 and failed. I found while searching today that the rebuild (renew) kit number might be part #37-1537 & the trick kit listed as #37-933.  I am not familiar what the trick kit is unless it has something to do with a more aggressive motor. And as far as the gear ratio, I am tired of seeing and hearing the motor labor at 3000 rpm at around 50 mph; and I get horrible gas millage. Concerning small motors, I bought a Sears leaf blower 3 years ago and it has went to them each year for a piston replacement. (warranty) At least that's what the repair order states. It runs on 40:1 ratio and that is all I ever used. Have about 4 gas cans with several different mixtures to match up to whatever tool I'm using. PITA if you ask me. Back to the 4175 Holley, I'll try searching again for it and also try Advance, Auto Zone, and NAPA to see what they might have. My air cleaner sits very close to the top of the carb. It appears to be low profile. I might just need to buy a lower profile filter and see what happens. I know a lot of inline gas filters are installed right in front the right cylinder head between the fuel pump and the carb. Do you guys run with this setup or do you place it somewhere else? And I assume most use the metal instead of the see through? Appreciate the responses, Thanks,  J.R.

[janobyte]

Just my suggestion:Brand:AED Performance

Manufacturer's Part Number:4175

Part Type:Carburetor Rebuild Kits

Product Line:AED Ultimate Performance Carburetor Kits

Summit Racing Part Number:AED-4175


Lose the filters in the carb---yes you can run an inline between the pump and inlet to carb---just secure it. I always use the see through. Trick kit might be more $$ than you need to spend. Car ran fine before you said---fix the problem for less than 50 bucks, it'll run fine again.  Oh switch to Klotz or Amsoil Synthetic for the 2 strokes ,50:1,and run them dry ,alcohol kills them. Had no issues when my boys where younger racing dirt bikes--1 gas can.

[janobyte]

How is the car running ?

[adjudimo]

Janobyte, All I have been able to get done so far is remove the carb. Too many people requiring my time spent elsewhere. But, it's the Holidays; so I don't really mind. I did notice that the intake crossover hole on the driver side was plugged up with a bunch of crud. Pass side was clean. Cleaned it out some while holding shop vac over opening. Didn't go too far. Was afraid of trash falling through into valvetrain. I have done more research on several chevy based forums (corvette, chevelle, etc.) and just reading, a lot of people recommend putting a Quadrojet back on these particular 396/325 engines for both gas millage and still have good power/throttle response. I would actually like to try one, just to see if I would be satisfied. I guess that's another search to find out which one is appropriate for my car. Since they are spread bore, that would require me to stay with a spread bore design with high rise aluminum intake if I go that route and also other carbs considered due to trying to keep hood clearance proper. My cast iron intake is a high rise, but still considering an aluminum intake. Lighter and just looks better in my opinion.