Swapping out OEM distributor with HEI distributor

[TotalyHucked]

My truck the ESC went down . I put in a regular HEI I messed with it springs,weights,vacuum can initial. I never got it to run as a total package as well as it did with ESC. Same with @SirRobyn0 he chronicles all the changes he made over the coarse of a year,finally when it was all said and done,it was back as an ESC truck. He documented it all recorded gas milage etc. I can tell you mine runs better with esc. But I didn't documented anything. Working ESC is best in my truck. I suspect yours never worked right. So it's real similiar to the I took off a messed up Qjet and put on an Edelbrock and it runs great. But you never hear anybody say I compares a good Quadrajet to an Edelbrock.

Yeah, I read through that thread and think he's nuts lol. Trust me, I get what you're saying. But for the effort it takes to get it there and source the parts, especially when you're talking a lowly 305, it's not worth the hassle IMO. Better to just stab a regular distributor in, set it and go.

 

[Rustisbest]

Old doesn't mean bad, new doesn't mean good. Mine and countless others run great without it. High compression and all. We agree to disagree.

 

[boloboss]

Question:
about the 9-volt stock resistance wire going to the old distributor...since I swapped to the HEI, do I need to change that resistance wire to 12 volts? And if I don't what are the disadvantages

 

[Ricko1966]

Question:
about the 9-volt stock resistance wire going to the old distributor...since I swapped to the HEI, do I need to change that resistance wire to 12 volts? And if I don't what are the disadvantages

You don't have resistance wire,that ended like 1974.

 

[Rustisbest]

Sure it does. I can set my timing where the truck runs good on a 50 degree day with no load or 90 degree day pulling a trailer. Because timing demands change,and esc adapts.GM designed it and installed it for a reason. Yes even 350s started getting ESC 1983 ish. Small blocks didn't used to have HEI at all,but people upgrade to it. I consider knock sensor an upgrade. So did GM.

You've put it on the 75 C20 in your avatar?

 

[Ricko1966]

You've put it on the 75 C20 in your avatar?

I have several trucks,that ones getting a 6.2. Yea I know those suck too. But it suits my needs,pull trailers and get reasonable milage.

 

[Ricko1966]

Old doesn't mean bad, new doesn't mean good. Mine and countless others run great without it. High compression and all. We agree to disagree.

Yea I never said a stock HEI didn't run good I,'ve run lots of them. I even told the O.P. in post like 12 or 13 he's already changed it. It's not worth changing back. HEI and an ESC HEI are the same distributor,with the exception of the module and pigtail.Weights,springs,pickup coil,vacuum can etc. all interchange. To make a ESC distributor non esc all you have to do is splice wire a to wire c. I personally think having the ability to run more timing is an advantage. But I never said a regular HEI sucks. I also said around post 15 I don't want to argue about why I think ESC is better. But because some people wanted to know. I went there. I regret responding now.

 

[Ricko1966]

Well guys that's what I have a stock 350. So from all the info this tells me that the engine had to be swapped before I got it from a 305 because it had that type of distributor with the ESC)

8th digit of VIN will tell you what engine it had originally.Some 350s got Esc. 1984

 

[Bextreme04]

Are you sure that only the 305 came with the electronic HEI? Both my Big block truck and my 350 small block truck have those wiring harnesses hanging there doing nothing.

You are equating HEI=ESC... that is not the case. HEI came in all squarebodies from 1975 on. ESC was ONLY on LE9 engines(305). The timing control that came into the TBI, TPI, and later EFI systems is very different than the dumb knock retard only ESC that was in the LE9 used in the trucks. It is an especially terrible and unreliable system between the type of sensor used, the location it was installed, and the computer that was reading the signal.

 

[Rustisbest]

Ricko I know theyre the same distributor more or less. We bypassed it on my dad's 85 GMC and eventually stuck a regular HEI in it with all new stuff in it when it went to my nephew and set it like every other SBC prior. My thoughts were they had a real low base timing (like 6 or 8) to drive up combustion chamber temps to reduce EMISSIONS. That makes em prone to detonation.

The vacuum canister added like 20* of timing to get it back to what it should of been in the first place at cruise. I treat em all the same. 10-14 base, 20 centrifugal and 12-16 on manifold vacuum. I never said knock sensors were bad. Just that this ESC system was unnecessary. It doesnt learn or retain any info like modern EFI stuff.

 

[boloboss]

Say guys matters if we argue disagree, to disagree or whatever. I'm just glad we have this community to exchange knowledge... valuable knowledge!!!! I appreciate every last one of your comments and responses

 

[Ricko1966]

.

Ricko I know theyre the same distributor more or less. We bypassed it on my dad's 85 GMC and eventually stuck a regular HEI in it with all new stuff in it when it went to my nephew and set it like every other SBC prior. My thoughts were they had a real low base timing (like 6 or 8) to drive up combustion chamber temps to reduce EMISSIONS. That makes em prone to detonation.

The vacuum canister added like 20* of timing to get it back to what it should of been in the first place at cruise. I treat em all the same. 10-14 base, 20 centrifugal and 12-16 on manifold vacuum. I never said knock sensors were bad. Just that this ESC system was unnecessary. It doesnt learn or retain any info like modern EFI stuff.

Oh yeah GM had dozens if not 100s of combinations of weights,springs,center cams,and advance cannister. I've done more than my share of recurving GM HEIs. I don't want want to beat on this anymore,Personally I like the ESC especially if the distributors are curved the same. That or a putting a D1941 5 wire module in a 4 wire HEI, that,allows you to pull 5* on demand like going up a long hill pulling a trailer it's not fancy or complicated just does what I like. The D1941 is not the 5 wire truck ignition module.