First hei installation

[66 Stepside C X]

Yesterday I finally got around to installing my HEI, into stock l6 250. Everything fired up.. and set the timing to 10 degrees right were the A mark is... but giving it that much advance seems like it’s setting the idle too high 900-1000rpm were anything I do with the carb with the mixture screw or idle screw are almost having no effect.
I will try bringing down the initial timing just strange that everything I’ve read says 10-14. my vacuum is reading at 19-20. I know there could be a lot of variables i am sure, but before changing to HEI it was at 4° and idle was 650rpm with around 16-17 vacuum. Any suggestions will be helpful. When I did first get it started the timing was at 0, and i slowly turned it up to 10 which raised the idle.

thank you all for any and all the help.

[geezer#99]

New hei or an old used one?
Are you plugging off the vac pot while setting initial?

[66 Stepside C X]

brand new cardone not rebuilt. yes vacuum line disconnected and plugged at distributor end.

[66 Stepside C X]

wait.. what the vac pot ? is that something else i need to plug?

[geezer#99]

Ah! No!
You say you plugged off the line.
Vac pot is what it was connected to.
Have you done anything else at the same time. Like carb work, linkage maybe?
Does it start good hot?
Does it diesel (run on) when you shut it off?

[66 Stepside C X]

this is how i have it plugged with screwdriver in rubber line

[66 Stepside C X]

Originally Posted by geezer#99

Ah! No!
You say you plugged off the line.
Vac pot is what it was connected to.
Have you done anything else at the same time. Like carb work, linkage maybe?
Does it start good hot?
Does it diesel (run on) when you shut it off?

so i need to plug the small metal nipple coming off the distributor and the rubber line or just the metal nipple?

nothing else has been done, and yes with the high idle it did run on for a second or two after shut off. but i did that before as well when i was adjusting my carb before HEI when the idle was set too high

[66 Stepside C X]

i only started it up once from cold, and kept tinkering with the idle and mixture and timing until wife started yelling at me to come to bed. So i havent had a chance to start from hot

[geezer#99]

Just the hose plugged is all that’s needed.
Golf tee works better.
Even though it’s new you should check the weights and springs in the distributor. Pop the cap off and turn the rotor slightly and you should feel or hear the weights moving.
Also check end of vac pot link to see if it’s good.
Post a pic or two of your carb.

[66 Stepside C X]

Originally Posted by geezer#99

Just the hose plugged is all that’s needed.
Golf tee works better.
Even though it’s new you should check the weights and springs in the distributor. Pop the cap off and turn the rotor slightly and you should feel or hear the weights moving.
Also check end of vac pot link to see if it’s good.
Post a pic or two of your carb.

well that's good to know as i am starting to get more into golfing.
I will go ahead and check weights and springs
what exactly should i be looking for on the pot to make sure it is good?
I will also take some pictures of the carb.. anything in particular you would like to see( a certain angle of the carb ).

If everything checks out okay what would be my next move.. could i have dropped the distributor gear incorrectly and it still fired up? 180° wrong way? I did read that the oem work manual for HEI 4.1 is 8° for that year model. but as i mentioned seems like that's not the case with what everyone recommends here

Thank You for all help, I really appreciate it

[geezer#99]

You want to make sure the link arm is moving.
There is a manual test.
Hook up a long vac hose onto the pot nipple and draw a vacuum on it. Use your lungs and
suck on the hose. You should see the plate in the distributor moving.
Pics wise. Just front, back and sides if possible.
If it’s running it can’t be 180 degrees off. Or can it be off a tooth.
There is a possibility your balancer mark is wrong.

[geezer#99]

Did you run a dedicated 12v power wire to the hei?

[66 Stepside C X]

Originally Posted by geezer#99

You want to make sure the link arm is moving.
There is a manual test.
Hook up a long vac hose onto the pot nipple and draw a vacuum on it. Use your lungs and
suck on the hose. You should see the plate in the distributor moving.
Pics wise. Just front, back and sides if possible.
If it’s running it can’t be 180 degrees off. Or can it be off a tooth.
There is a possibility your balancer mark is wrong.

i will try the test this week to check. good thing im not a smoker.
i was thinking maybe the balancer could be off as well.. but again I have no idea if it is or is not. is there any other way to check the timing if the balancer is off? I guess if im running good base idle, good vacuum pressure and am not having any issues ill be okay, im not racing in it just weekend cruising. But I do want to make sure everything is properly set up timing/ignition wise.

when you say it can be off a tooth.. would it still start then..? its dropped in all the way snug.

yes i am running a dedicated line.

thank you again

[geezer#99]

I meant that people use the excuse that it’s off a tooth to explain what timing is wrong, or hard to set.
Truth is you can be off 5 teeth and still run the same with the same timing but just be sure to have the rotor pointing at the #1 wire on the cap when #1 is at tdc compression.
You can have #1 anywhere on the cap but people tend to have #1 cap terminal pointing at #1 plug.

[66 Stepside C X]

Carb pictures

[geezer#99]

What’s the white fitting with the hose on it for?

[66 Stepside C X]

Originally Posted by geezer#99

What’s the white fitting with the hose on it for?

That’s just the vacuum gauge threaded into the intake manifold to read the pressure. Figure I’m still going to be adjusting to might as well leave it in until I have everything straightened out