Factory choke work with a blocked Exhaust Cross Over?

Yes, its the well choke. I'm at 3900 feet. One one of my cars I did go with the electric which works flawless, but with this car I really want it to look stock, course frustration can bring about compromise.

I'll play around with the spring and rod length and maybe even drill a hole in the block off before I give up.

As mentioned, it's a "time" thing. Engine heat will eventually warm up the choke spring and it will function normally, the heat crossover just speeds up the process. IMO the minimal gain in blocking off the heat crossover to gain a few HP by keeping the carb cooler on a street driven car in variable seasons isn't worth the headache. You can accomplish the same basic thing by adding an insulation plate under the carb, there are some made that are the same shape as the gasket, you'll need to adjust the choke (gasket underneath it) or the rod (lengthen it) to accomodate any added hieght from the added gasket thickness.

Looking back at your original problem, avoiding percolation or vapor lock or whatever is going on, maybe it is not a good idea to try to solve one problem by creating another (choke)

First and easy - is the fuel line insulated? If not, that can make a huge difference. Is the filter or any part of the line real close to the exhaust system? Gotta move it if so

Is the fuel tank venting system working correctly? Old lines, rust, etc... can be a headache. Open the fuel tank filler when it does this and see if you get a huge rush of vacuum or pressure

Make sure the bowl vent on the carb is working properly - you want those vapors that build up when sitting to be able to get out

try the phenolic spacer -

http://www.edelblog.com/tech-tips/resolving-heat-soak

p.s. we have made tons of custom length choke rods out of simple aluminum rod. I forget now what dia we used, but it was probably 1/8". it's also a trial and error thing when adding carb spacing in addition to tuning the spring rate, but you can always make it too long and then bend some extra angles into it to shorten it up. and if you're real keen on factory look, once you dial in the right length, just make a new one directly that size

I could never make my stock choke work with the manifold heat blocks so took them out, works fine now. That change along with the ethenol-free gasoline has the GTX running great!

One approach to blocked cross-overs and a fully functional factory style divorced choke.

That is a trick set up on the 6 Pack choke! I may go that route.

So a good point was brought up about focusing on the fuel peculation problem. Well, that's on another 440 but I'm worried having the same problem with this 440 which will go in another car. So I've changed the carb and put a new, Summit 750 Holly designed aluminum, which runs great. Starts great all the time except when I go to hot start it with in say 45 minutes after shutting it off. In trying to fix the problem I isolated the fuel line so that it does not touch the block or other engine accessories, added a plastic spacer, blocked the heat cross over and went to an aluminum intake in hopes of dissipating heat.

What do you suggest I use to insulate the fuel line?

My next move is to install factory valve covers so that I can hook up the gas tank vent to the valve cover breather (70 cuda 3 nipple breather). Maybe add the 440 vapor seperator that goes along with the fuel filter. Last is to buy a heavy, non aluminum carb. But I will try a carb shield.

Thanks!

Electric fuel pump with a return regulator

My manifold heat crossover is blocked plus i have a 1/2" 4 hole spacer under the stock AVS and on start up i pump the pedal 3 times this closes the choke and sets the fast idle it starts fine choke opens fully on start up via the choke pull off, and it stays on high idle till i decide to kick it off. Of course the rod from the choke t-stat is adjusted to not engage. I live in Chicago and have no problems on colder fall nights.