What spacer are you guys running on 340s? I have seen previous posts on a phenolic spacer helping for hard start hot. I have to bury the pedal WOT for 3-5 seconds of cranking, The 340 is basically stock except for holley carb. I want to keep it stock looking without going too deep on a spacer. thanks!

I suggest Cool Carb products. This guy makes carb spacers and carb heat shields. I bought the carb spacers and a heat shield for my 340 but I am not after the stock look. The carb spacers come in different thickness's. Real nice guy too.

http://www.coolcarb.com/order-products.html

This is a picture of the Cool Carb carb gaskets.

Did they seem to do the trick for you? Did you put them both on at the same time or one before the other?

I use a bottom spacer, then the heat shield, then another spacer on top. I have always had them on in this order. So far this Spring, the fuel in the bowls only rises about 1/16" during the heat soak process when the engine is shut off with the hood closed. When I first installed them, I would check the fuel level every five minutes to see how high the fuel would rise in the bowls. Since running this setup, the fuel only rises about 1/16".
When the engine is running or after a drive when the engine is idling, I can feel the carb and it is lightly warm at worst case. These Cool Carb spacers and heat shields are good to 300 degrees. I run a 195 degree thermostat and I have not had any issues with these items this Spring. The summer will be a good test though.

Thanks for the info, I havent measures how much it rises, but when shut off after hot, all I can here is the fuel boiling over and hitting the intake. I dont want to add the shield for the look ,I'll try the spacer first, smaller to bigger I suppose.

Your welcome.

The material that this guy uses was designed by the company that he used to work at. It has a thin sheet of aluminum on the top and on bottom and it has some type of heat sink material in between. It appears to be a good idea for heat insulators.

Are you sure it's a carb issue and not a lack of initial timing. That's a classic issue for insufficient initial timing, long cranking when hot.

None of my 340's do that and I likely live in an area MUCH hotter than most on here.

I thought of that, that may be my next move. Is it better to get hot and adjust until it starts better hot? I do hear the gas boil in the carb though

I run a 3/4 inch to 1" spacer and electric pump never a problem no matter how hot it gets

Block yer heat crossover.

Use the intake manifold gaskets that block off the exhaust crossover. An electric fuel pump with return works great, but even the mechanical pump with vapor return helps prevent vapor lock.

The pump gas sold today boils and evaporates really easy compared to the fuel these cars originally used. A friend filled two masson jars, one with race gas and one with pump gas. The pump gas evaporated much sooner and left some nasty residue from all the additives. After the race gas evaporated, there was almost no residue. The glass did have slight tint from the coloring used in the race gas.

Regular 4 hole 1/2" phenolic spacer on my stock 340, cured my hot restart problems!

Best $15 I've ever spent.

These Edelbrock heat insulator gaskets are designed to help prevent fuel percolation in Performer series carburetors exposed to extreme underhood temperatures. They're available in both open and ported styles, and come complete with extended-length carburetor studs.

http://www.summitracing.com/parts/EDL-9266/

Well I played around a little bit more in the garage. I noticed it has a spacer of sorts between the carb and intake, I missed that before, just didnt notice, just bought the car. I ran the car for probably 5-8 minutes to bring the temp gauge up. By no means was it extremely hot. If I shut the engine off and immediately restarted it starts perfect without the gas pedal. If I shut it down and wait about five minutes it wont restart unless I put it to the boards. Dont think its a fuel delivery problem for there is fuel squirting in. I added some timing and it ran a little nicer but didnt really help starting. I may need to play with the timing a little more or do something about the ignition, possible upgrade. I like to keep it as stock appearing as possible though, hurts when trying to make a driver out of it.

Here's my Cool Carb spacer from my one barrel slant six....

This is after one hour of driving.

Looks like a blown out condom?

What's wrong with reg old wood or phenolic?