I finally found a carb spacer for my 300/6 1 bl that doesn't have the EGR attachment. I also put an open breather and open air cleaner on it. I didn't make any other changes, but the engine breathes a lot better. Where before it accelerated like it was dragging an anchor, now it feels much more free and willing to rev. I don't know if I added any horsepower, but the part-throttle performance is definately improved.

I found the spacer on a mid 80's Econoline van. It was a perfect fit for my truck, but it's 1/2" shorter, so I had to change the mounting studs.

When trying to do stuff like this, go to NAPA. We have AutoZone and Advance Auto stores, but they're completely useless. In our town the NAPA guys know cars and trucks. As far as the other two go, if it's not in their computer, they're lost. For example, I took the old studs with me. They're 3" long with fine threads on one end, and course on the other. The AutoZone guy said, "What year truck did it come out of?" I said, "It doesn't matter because I need studs 1/2" shorter then these." He couldn't help me because he couldn't "look it up." I went to NAPA and they had a whole cabinet of studs, all sizes. The guy found the ones I needed and I was on my way.

 

I'm glad you found one. I looked last weekend for you but someone snaked it. How hard was is to find? I have only seen one around here and was debating making a drawing of the one I have for others. It would be easy to fab with a mill. Yeah, I know what you mean about part stores. Most have crap for quality and a lot of these new people couldn't tell you the difference between a standard nut and a jam nut or a 3/8-16 and a 3/8-24 stud. It's pretty sad, but what do you expect for 4.25/hr these days?

 

Thanks for looking. I found it at the third junk yard I looked at. I learned a lot. My truck is a 79, but I saw 300/6's identical (and I do mean identical) to the one in my truck in ones as new as 83, but naturally they all had the EGR attachment. The 73-79 pickups were pretty well under-represented, and of the 300/6's I saw, the vast majority of them had the manifolds and carbs missing. Apparently they're either all still on the road or they've been crushed. The two junkyards I struck out in had mostly newer vehicles. There's a crushing yard very close to them, so they may not save older vehicles.

It helped that I had posted here before hand and you (or it may have been someone else) alerted me to the fact of that carb/manifold combination being used on a variety of different vehicles, because I ended up finding the part on a Ford van, mid 80's vintage.

I tell you what else I'm going to get next time is another alternator mounting bracket. I'm going to take it and cut off the air-pump attachment (it's all cast as one piece). This way I can save the one I have in case I ever need it. In fact, I saved all of the parts I removed, but I'd sure hate to put them back, the truck runs big-time better without them.

I have the timing set to stock (I don't remember the value). What do you think about advancing it until the engine knocks under load and then backing off a bit? With the better air flow, will the engine tolerate more advanced timing better?

 

I've never had much luck advancing the timing on my 300, nor have I ever had a problem with it. I tried advancing once a few degrees, but the fuel mileage suffered. If you check on that same van and find it has no attatchment for the smog pump on the alternator bracket, there's a good chance you ID'd a HD 300 with the forged steel crank. Usually tell tale sign is lack of emissions equipment - check the VECI label.