Duraspark II

[emunder]

Have to have the non-EGR, non-feedback carb though for the Duraspark setup to work correctly though right?

A DuraSpark II ignition system would have originally used a non-feedback carburetor and a DSII-specific distributor that are both calibrated to be used with EGR and other emissions equipment.

You can use the DuraSaprk II ignition without EGR, but choose a carburetor that is not calibrated for EGR. Aftermarket carburetors like the Holley 390 are not calibrated for EGR. The easiest way to to do this is to find an older, stock FORD carburetor that was used before EGR (and other emissions) and one that closely matches your engine, transmission, and type of vehicle. The 1970 F350 carburetor you are referring to is a good example.

You will also need to re-curve your distributor so it is calibrated to run without EGR for the reasons Gary mentioned. There are a couple of places that sell DSII distributors that are calibrated to your specific engine combination.

Capiche?

Ok I see what y'all are saying. Then in theory what I would like to do is convert over to DS2, get the proper distributor & coil, leave the stock intake manifold in place & install the EGR non-feedback carb, install EFI exhaust manifolds with the Walker Y-pipe, pull the smog pump & cat, and install new exhaust from the Y-pipe back.

Question though...in removing the air pump does it not hook up to the EGR, if so how do you block it off once the smog pump is removed?

I don't have emissions inspection in Texas since my truck is over 30 yrs old so I'd like to just take all that crap off.

[Rembrant]

...leave the stock intake manifold in place & install the EGR non-feedback carb...

Do you mean a NON-EGR NON-Feedback carb? Or are you trying to keep the EGR system?

I am no 300/6 expert by any means, but there have been quite a few discussions on here about factory NON-EGR spacers...of which there are a few different styles I believe. You can see one of several discussions below:

http://forum.garysgaragemahal.com/Non-EGR-spacer-for-300-4-9L-D7TZ-9A589-H-NOS-td19341.html

Or, as far as I know, most people just remove the EGR pipe and bolt a plate over it, or cut the end of it off and have it welded shut. Some good pictures in the thread linked below:

http://forum.garysgaragemahal.com/Questions-regarding-duraspark-conversion-td18255i20.html#a18389

If you Google the topic, you'll find where some people went to great lengths cutting everything off the EGR spacer and then welding it all closed.

If you're going back to 1960's or early 1970's era emissions (or lack thereof) you'll just need a single vacuum line for your distributor, a vacuum line for PCV, and a vacuum line for your power brake booster.

Everything else can go. (I'm speaking from 302 experience, not 300/6, but I went through this process myself and removed everything).

 

[emunder]

...leave the stock intake manifold in place & install the EGR non-feedback carb...

Do you mean a NON-EGR NON-Feedback carb? Or are you trying to keep the EGR system?

I am no 300/6 expert by any means, but there have been quite a few discussions on here about factory NON-EGR spacers...of which there are a few different styles I believe. You can see one of several discussions below:

http://forum.garysgaragemahal.com/Non-EGR-spacer-for-300-4-9L-D7TZ-9A589-H-NOS-td19341.html

Or, as far as I know, most people just remove the EGR pipe and bolt a plate over it, or cut the end of it off and have it welded shut. Some good pictures in the thread linked below:

http://forum.garysgaragemahal.com/Questions-regarding-duraspark-conversion-td18255i20.html#a18389

If you Google the topic, you'll find where some people went to great lengths cutting everything off the EGR spacer and then welding it all closed.

If you're going back to 1960's or early 1970's era emissions (or lack thereof) you'll just need a single vacuum line for your distributor, a vacuum line for PCV, and a vacuum line for your power brake booster.

Everything else can go. (I'm speaking from 302 experience, not 300/6, but I went through this process myself and removed everything).

@ Rembrant:

Figured I'd just leave the EGR system intact and use a non-feedback EGR carb. This way I won't have to have the dizzy recurved. What I was wondering is what happens when you remove the smog pump? Doesn't it tie into the EGR somehow? Think I understand everything else..

[ArdWrknTrk]

@ Rembrant:

Figured I'd just leave the EGR system intact and use a non-feedback EGR carb. This way I won't have to have the dizzy recurved. What I was wondering is what happens when you remove the smog pump? Doesn't it tie into the EGR somehow? Think I understand everything else..

Nope.

The Air Injection Reactor/tion system has nothing to do with EGR.

It provides air/oxygen to the exhaust & catalytic converter under certain conditions, in order to oxidize/combust remaining hydrocarbons before they escape to the atmosphere.

EGR provides inert exhaust gas (NO oxygen) to the intake charge under certain conditions in order to slow combustion and allow more spark advance without knock.

[Rembrant]

@ Rembrant:

Figured I'd just leave the EGR system intact and use a non-feedback EGR carb. This way I won't have to have the dizzy recurved. What I was wondering is what happens when you remove the smog pump? Doesn't it tie into the EGR somehow? Think I understand everything else..

Sorry Emunder, I'm not much help here. When it comes to removing emissions systems, it seems like most folks take an all or nothing approach. Either it all stays or it all goes. So having said that, I don't know anything about retaining only the EGR.

[ArdWrknTrk]

@ Rembrant:

Figured I'd just leave the EGR system intact and use a non-feedback EGR carb. This way I won't have to have the dizzy recurved. What I was wondering is what happens when you remove the smog pump? Doesn't it tie into the EGR somehow? Think I understand everything else..

Sorry Emunder, I'm not much help here. When it comes to removing emissions systems, it seems like most folks take an all or nothing approach. Either it all stays or it all goes. So having said that, I don't know anything about retaining only the EGR.

You can keep the EGR system intact and NOT have to change the distributor, but you need to keep the thermal vacuum switch and green vacuum lines.

[Danny G]

Nope.

The Air Injection Reactor/tion system has nothing to do with EGR.

It provides air/oxygen to the exhaust & catalytic converter under certain conditions, in order to oxidize/combust remaining hydrocarbons before they escape to the atmosphere.

EGR provides inert exhaust gas (NO oxygen) to the intake charge under certain conditions in order to slow combustion and allow more spark advance without knock.

If the AIR pump and the tube going to the cat are gone will this cause negative affects if the cat is kept in place (clogging?). At that point would you remove the cat?

[ArdWrknTrk]

Nope.

The Air Injection Reactor/tion system has nothing to do with EGR.

It provides air/oxygen to the exhaust & catalytic converter under certain conditions, in order to oxidize/combust remaining hydrocarbons before they escape to the atmosphere.

EGR provides inert exhaust gas (NO oxygen) to the intake charge under certain conditions in order to slow combustion and allow more spark advance without knock.

If the AIR pump and the tube going to the cat are gone will this cause negative affects if the cat is kept in place (clogging?). At that point would you remove the cat?

The oxygen helps it 'fire off'

Remember, these were early days and rather crude combustors.

If I had to have a cat, I'd probably go with a newer 'universal' cat that didn't take air.

Though:

A) My truck (over 8500) never had one.

B) The trucks Cats are still far away from the exhaust ports.

Newer cars have them integrated into the manifold, so start times are quick.

If the truck is tuned well, and driven some distance, I don't see a problem.

If the choke never opens and it only goes 3-10 miles at a time I can see a cat getting coated.

[Danny G]

The oxygen helps it 'fire off'

Remember, these were early days and rather crude combustors.

If I had to have a cat, I'd probably go with a newer 'universal' cat that didn't take air.

Though:

A) My truck (over 8500) never had one.

B) The trucks Cats are still far away from the exhaust ports.

Newer cars have them integrated into the manifold, so start times are quick.

If the truck is tuned well, and driven some distance, I don't see a problem.

If the choke never opens and it only goes 3-10 miles at a time I can see a cat getting coated.

Yea per the PO the truck had not seen very much highway driving before I bought it. A lot around the neighborhood, and farm/field. With the cat tubes not even hooked up, and the air pump gone it would not surprise me if the honey comb in there is all coated up. I know cats are pretty important to cutting out the nox etc from emissions so a universal one sounds like a responsible (albiet expensive) replacement. If it is nasty maybe ill play with putting it in the sonic cleaner lol and hook up a pipe patch in the mean time.

That being said there is no emissions checking in SC I could run straight pipes all the way back with no cats and no muffler and be perfectly legal, but from my understanding lack of at least a little back pressure decreases your fuel efficiency.

[emunder]

Yea per the PO the truck had not seen very much highway driving before I bought it. A lot around the neighborhood, and farm/field. With the cat tubes not even hooked up, and the air pump gone it would not surprise me if the honey comb in there is all coated up. I know cats are pretty important to cutting out the nox etc from emissions so a universal one sounds like a responsible (albiet expensive) replacement. If it is nasty maybe ill play with putting it in the sonic cleaner lol and hook up a pipe patch in the mean time.

That being said there is no emissions checking in SC I could run straight pipes all the way back with no cats and no muffler and be perfectly legal, but from my understanding lack of at least a little back pressure decreases your fuel efficiency.

Thank y'all so much, I really appreciate it. Gonna get started ordering some parts so I can get the ignition converted over to the DS2. I really don't mind buying another distributor...they are pretty inexpensive.

On another note....when I was exploring the idea of trying to omit the EGR I did come across this manifold...looks like it does not have the EGR hole. Couldn't find any information on the part number but if you wanted to omit the EGR that would be a pretty simple fix instead of scouring the internet for the carb plate that covers the hole...they seem to be extremely hard to find. Have y'all seen this manifold before?