340 intake decisons nightmares

[mikerallye]

I removed the factory intake on my 73 340 this morning for the sole purpose of blocking off the heat transfer egr holes. First thing I noticed was that the factory intake weights a ton; and my first question is: I am not joking here; I am seriously considering using my engine hoist to put it back on, if I even put it on at all! How can one person gently let it down onto the block without destroying the gaskets? 
Next thought: I love the idle to 5500 rpm power of the stock intake and cam, but if I put on an RPM Airgap that will raise my power curve to 6500, right? What will happen If I leave the stock cam in it? The stock cam specs are: .429 /.444 lift. Will I notice any difference while driving it.
The reason I am considering the RPM  Airgap intake is weight, and hopefully it will not boil the fuel out of the carb, (my current problem.) I would put the Performer intake on it if it was an airgap design, but it is not offered for Mopar this way.
So, Will the RPM AIrgap solve the fuel boiling issues? Will it hurt off idle performance? Will it work the stock cam?
Will the Perfomer solve the fuel boiling problems?   

[Oldschool]

I think that a nearly stock 340 would not pick up anything with the Air Gap.  In fact, you may even lose a little on the bottom end.  I would recommend an Edelbrock LD340 or equivalent.  It is a dual plane like the stock one, except it is aluminum for weight savings, and it works a little better than stock.  Not sure where to get one....       

[NoMope Greg]

I think that a nearly stock 340 would not pick up anything with the Air Gap.  In fact, you may even lose a little on the bottom end.  I would recommend an Edelbrock LD340 or equivalent.  It is a dual plane like the stock one, except it is aluminum for weight savings, and it works a little better than stock.  Not sure where to get one....       

   The Air Gap won't raise your power curve to 6500 rpm - the rating means that it will breathe well up to that rpm, but if your engine isn't capable of running that fast, the Air Gap will do nothing for it.  First place I'd look for an LD340 would be 

[mikerallye]

The LD340 is an old design right? Is the Performer its replacement?
The RPM Airgap's appeal to me is the air gap will let it run cooler; I don't care if it will let my engine rev higher; mainly, will it hurt its drivability on the low end?

[422STROKER]

I don't thnk it will hurt too much it is still a dual plane intake.  it will allow you to grow a bit later as well.  I noticed you have headers so it would be a worthy match to those as well.  It should help with the boiling, but will take a little longet to warm up since there are no provisions for the exhaust crossover.

Tom

[The Cuda Guy]

This is the intake I would go with... if I was in the market.   

http://store.summitracing.com/partdetail.asp?part=WND%2D8022&autoview=sku

Don

[mikerallye]

The Weiand certainly has a good broad power band. It sounds too good to be true. I wonder why Edelbrock limits its rpm 1500 to 6500. Anyone here tried the Weiand?

[wally426ci]

Mike, how about an aluminum or carbon spacer? im running a stock 69' 340 intake with a 1" riser and it clears the raised Challenger hood.

And, i think Mopar Performance sells an Aluminum replica of the Cast Iron....

[mikerallye]

I haven't though about the Mopar intakes. The main reason for the change is fuel boiling in the intake. Are you having this issue on hot days?   

[wally426ci]

well, so far i havent. i was running a 160 thermo and through all of my rediculous 6 month troubleshooting, i switched to a 180. it didnt really make a difference. I was thinking you could try running a little cooler.... have you had this problem before? or did you change something and now it does this?

I went through a million things, and after all this time i wound up having a week 12v connection.....  Im just wondering if fuel boiling is the absolute problem? or if it could be something else......

Its so frustrating to be there, i must have checked for updates 10 times a day while i worked on it.. 

oh, and i just did the spacer for the heck of it when i built this motor... no real reason.

[MEK-Dangerfield]

Mike,

  A carb spacer can work wonders. I have a 1/2" spacer on mine since I don't have a Ralley hood(clearance issues). Getting that carb isolated from the hot manifold will really help you.



   Mike

[vinb]

You are probably not going too find a nice LD340, so the equivalent would be a Weiand #8007.
Summit/Jeg's sells them.
If you don't have the cam, springs or heads 6500 rpm is out of the question...

[mikerallye]

Nice looking intake. Does it run cool in July? The problem started this month. It melted the rubber off of the needles , started to flood at stops, so I replaced the needle and seats (edelbrock 600) . The flooding stopped, but I bet it will ruin these needles too in a short time. You can  hear it boil when its shuts off. I have to crank on it for 10 -15 seconds before it will start. I have read posts here about this same issue. I have the Mopar 1/4 in carb spacer/gasket and thats it. It runs fine now until its warmed up, the temp gauge reads 200. I had a 440 challenger with a performer intake and 750 eddy on it; it did the exact same thing. Finally made it to winter and the problem ended. There must be a simple solution to this very common problem. Thank guys   

[71chally416]

The Weiand Stealth Intake is just a clone of the stocker. I would pass on that. The Performer or LD340 will definately work better. I seriously doubt that the small passages in even the RPM intake will hurt your low end. The LD340 Intake has a heat crossover just like the stocker and will need to be blocked with some shim stock in the hot weather. You can even cut the top off a coffee can with some tin snips to make the shims. I've did that before. cut them wide and long enough to cover the holes and bend about 1/4" of the tops over to hold them in position on the top of the exhaust heat passage. They'll compress under the gasket fine as long as it isn't the cheap metal type. 

[bennydodge]

I did this same swap(stock iron for an Air-Gap) a few years back when my '73 340 was stock internally. It really didn't make a huge difference. It had better low end snap. I had to use an AVS carb(TQ wouldn't fit without a spacer) that was on the smallish side. These motors('72-'73 340's) have such low compression, nothing really helps. In reality, the stock iron spreadbore intake and TQ carb are pretty good. I never had ANY issues with heat, either. It would start easily when hot with the TQ; the AVS hated the heat. What really helps with the low-comp. 340 is a looser torque converter. Night and day difference with mine...