Yes I did, but none gave the temperature differential possible when using their product. IE:

In laboratory testing simulating typical under hood temperatures of U, fuel reached X degrees without our product

Repeating the test under the same conditions resulted in a temperature of Y or a drop of Z degrees

Nor did they respond to my requests for expected results. That indicates to me they don't know and likely haven't tested the product BUT will sell it to you

My 51 Plymouth is like that. Runs just fine, can set for weeks on end and fire right up. I don't use any special fuels or anything. Whatever pump swill is at the local Shell.

The interesting thing about this setup is that the factory flathead induction system sit right atop the factory exhaust manifold, the runners are nestled together as well. No phenolic spacer, no clothespins, no heat shields or anything. Mechanical pump.

I don't have fuel percolation or vapor lock issues. Others with similar setups do. I dunno why, unless that "contains up to 10% ethanol" is really E0. We do have one station in town that sells ethanol free gas, but I don't need to pay the vig for that as I don't have an issue.

I have an issue with a surge at idle after driving for awhile. I suspect since this is a stone stock 69 440 car that the carb is getting way too hot for the modern gas. If I put on a thicker gasket, will the choke pull off need a likewise raise? Will that still work when raised out of the well?

There used to be a 3/8 tall spacer that came in avs rebuild kits that might do enough for me. I used one on my last car with an aluminum intake and it worked great. I tired it back to back with a thin paper gasket and the slight hot start lag went away and the engine fired right off.

If the choke is currently working well and you raise the carb 3/8", the choke rod will either need to be lengthened by the same amount or a hollowed out spacer of the same thickness should be placed between the choke assy. and manifold heat well

I just went thru this on my wife's 74 Ramcharger with a 440. I ended up running a new 5/16 dedicated return line to the tank, re-configuring the tank, and using a fuel filter with a vapor discharge orifice to return to the tank. Here's a pretty complete write up I did on RamChargerCentral:

https://www.ramchargercentral.com/threads/74-ramcharger-36g-fuel-tank-upgrade-modification.332569


The truck would start to cut out and idling in traffic (ferry line which is 30 minutes to two hours waiting to get out on the island, Port Aransas, TX). I haven't gotten to the point in testing where I can say I *fixed* it, but if I continue to have problems, rather than insulate the line from the filter to the carburetor, I'm going to either build some heat shields to isolate it, or perhaps solder heat syncs onto the fuel line (like the little one used on computer chips). After watching a recent episode of engine masters where they tested header coatings and wraps, what I took away from that is that the insulation will hold the heat for longer if it was used on a fuel line. I get a 50* drop across my radiator with a shroud and fan which moves MASSIVE amounts of air. I also observed lowered engine bay temps after putting on the factory splash shields between the frame rails and inner fenders, I suspect that it has to do with the air being moved across the engine bay and down/out the bottom of the firewall now due to the addition of the splash guards.

Thanks

if using the thick insulator gasket the choke mechanism (OEM chokes) can be adjusted to compensate for the height.

Stuck my phone in there and got this. Could I just have the wrong pump? This doesn’t look like the “muscle car pump” Mancini has on their site.

Who has correct ones? Or if edelbrock still makes them with quality I could run one of those. They were good 15 years ago when I bought one.

Probably will need to run the thicker gasket under the carb still just because.

That's a normal looking big-block pump. Those are fine on a mild to moderate motor. I ran one for many years.

Just not rebuildable or clockable or "high flow" like the ones you see at Mancini's.

I doubt switching the pump by itself will make much difference to a vapor-locking problem.

do a fuel pressure test. looks like it could be a stock hipo pump but a pressure test is needed.

another thing to think about is adequate venting of the fuel tank. i did some tests on some pumps and an original hipo 440 pump pulled 19" of vacuum. in fact it pulled more vacuum than any pump i tested. if the fuel supply system isn't properly vented high vacuum in the lines can contribute to the fuel flashing.

As lewtot said above, fuel pressure is your friend, it raises the boiling point.

Ample pressure in the feed and ease of venting the other end will solve 90%
of your problems, my 2 cents....

Joe

Adding an electric pump to the feed has an added benefit of not having to crank the engine excessively to prime the carb after sitting for extended periods

My tank has lines going to the vent(s). Checked under there one day looking for a fuel leak. Saw they have newish rubber hoses on all the lines back there. When the tank is filled to the point of the deadman stopping the pump, I then can get an overflow out a vent, at least best I can tell.

This car appears to have multiple vents compared to what I remember on previous cars. Other ones I had ran the vent up into the frame rail and only had one best I can recall. This is a CA car and I’ve never had one before.

Maybe run the tank down and blow air through the vent lines?

Two things I thought about after my last post, if you have the three nipple filter/bypass,
check the vapor bypass outlet nipple, it's supposed to have a restriction, .060 if I remember.

Many of them came with no restriction, mine did (aftermarket), I had to solder it closed and drill the appropriate
hole through the solder.

Too large or no restriction will lower both pressure and volume to the carb.

On a Cal. car, I don't think the tank was vented to the atmosphere, so depending what you did with those 4 nipples,
you may have to drill a hole in your cap.

Joe

I had a 72 RR with a 440 and had the same problem and tried all kinds of stuff. Till it was all said and done the gas cap was a non vented cap so I drilled a small hole right in the center and no more vapor lock!!!

Carter still makes muscle car pumps that are probably a lot better than any other aftermarket OEM stock pump replacement pump are: up:
Summit sells them: scope:

I put on the edelbrock heat shield 3/8 spacer. Think it said it was actually .32 thick. Choke seems ok unmodified. I found a weird little heat shield sandwiched in there I couldn’t see before. It was an open piece on a stock dual plane. The new one has a divider down middle. Vacuum picked up on inch with the new one. Engine actually sounds little different too. I was able to screw the mixture screws in a half turn. Unfortunately it has the surge still based on my pulling it back into the garage for the day. Hot start seemed a bit easier.

I got a .595 drill bit and my new vapor separator bought from mopar mall is about that size. The old one that came in the parts box with the car has a HUGE orfice. Not even close. The shop that did the work for the last owner did some pretty shaky stuff, if they matched that, I might well have found the culprit. So next order of business will be to change the one they put on.

Also I grabbed five gallons of race gas and added a gallon, plus about 6 fresh 93 a couple weeks ago. Car seemed to do better, but still has an issue once throughly heat soaked. Like after a handful of hard runs and then town driving.

Might end up with a 180 stat. They had a 160 in the car that I didn’t care for so I put a factory 195 in. Maybe lowering under hood temps would help with this.

You guys always kill me with your some of the troubleshooting ideas...but don't stop trying
What is the under-hood temperature at the base of the carburetor with the hood closed after driving the car and all is at temperature??
You would be surprised.....
How hot does it get at the base of the carb after a heat soak?
I have to think it's hot hot under there, just because the temp gage says normal means nothing till the temps are checked.
Proper running engines do not require band aids

Good General Advice - Do whatever you can to keep heat away from the fuel. Carb spacers, insulated fuel lines, move lines away from headers, etc. If you have vapor lock, a mechanical fuel pressure gauge will start going down, down, down until the motor quits (I've had a lot of experience with vapor lock). Once the motor cools, it will fire right back up. FYI-I got myself home one night with a cup of Burger King ice in a shop rag placed on top of my center carb...got me home.

The reason fuel injected engines don't suffer vapor lock issues is because of pressure...not the return line. Most late model injected stuff is returnless fuel injection.