350 Distributor 4 wire plug

[RMrider17]

Hey I just finished doing an engine swap in my 85 2wd c10 from 305 to 350.

When doing the swap the old distributor decided to stop working, so I found another one but it is slightly different.

The original has a 4 wire plug that comes off of the back of it towards the passenger side and plugs into the stock wiring harness.

The one I found does not have this plug, so itll run but not that well.

Does that plug make my vacuum advance and mechanical weight advances work? because it also only has like 5 pounds of vacuum and im thinking its because it is out of time

Thanks
-Adam

[tommie]

82' has esc electronic spark control.

these are the wires that you see that hook up to the factory harness..

i like to use the older distributors, that did not have the esc and the extra wiring. and only had the 1 wire hook up.....

[RMrider17]

Thanks man, does that mean its gonna throw off my timing not having it?

[tommie]

on the 82' i had, i installed an older hei distributor that did not have esc.... no problems..

[raws67]

believe that HEI works in conjunction with a knock sensor. If the sensor thinks the engine is pinging it will retard the timing. Basically it will work in the opposite direction of your vacum advance. If you are no longer doing emissions etc etc then I think you can just swap to an older hei that doesnt use the esc. My 84 k-10 had a 305 I swapped in a 400 and gutted the computer and esc hei etc etc. There is a round plug going in to the firewall on the passenger side that will go to the computer and I dont think anywhere else. Then just look at what all those wires are going to and you will see what you can get rid of. But thats only if you can get away without doing emissions otherwise it will be expensive getting everything back together.

[Turbo85GMC]

Check out this article on swapping ESC & Non-ESC distributors:
http://www.73-87.com/7387garage/drivetrain/escrepl.htm

[Slonaker]

I replaced my ESC with a regular Mallory HEI when I did my 350 swap. No problems.

Slonaker

[RMrider17]

Alright thanks for all the help guys, so from what I understand is since I switched to an older style distrubutor from like a 78, I just eliminated the ESC, which is cool.

My final question is, do I have to remove the ESC from the computer on the truck side?, or can I just leave it the way it is and it won't affect my timing because it is not hooked up. Or does that one pink wire have to get spliced in with that other wire that leads to the BAT side of the cap.

[tommie]

leave it in there, does not affect anything