Well the suspense is over. I ordered new condenser, points, and plug wires from Rock Auto Wednesday. Came yesterday and installed today. I have a new HEI with a new set of Magnacores in the house. I still have to fiddle with the dwell, etc, but the truck runs 1000% better. But then it should- since it now fires on six cylinders instead of five.
So why did I go low-tech? The biggest reason was frustration. I've been fiddling with the truck for over three months and piddled and piddled. Time to get the engine running right and move on to other issues on it. I did buy it to drive
But also after reading Barry's initial post, I did some research and some thinking. Barry makes a lot of sense.
And I agree, I like simplicity- it's a virtue.
FWIW, I think the new HEI was fine, I expect I had a faulty wire to #6, since I got spark on five cylinders. But I've not bothered to test it anymore for the time being. I like sixes anyway, so this rig may get corrected and put in a Corvair, Pontiac OHC, GMC 302, or even a 292. Have to see if I can make it fit. I will say that physically, I found the eBay dizzy and the Magnecores to be clumsy in my truck. The HEI with it's coil on top was a tight fit in the firewall cove of my truck- there's not a lot of ways to get it in and turn it. With that, the wires could have used a few more inches, as they were close to being stretched when installed. There is so much more working room and slack with the original Delco-Remy and the noticeably longer Rock Auto wires.
HEI makes a lot of sense in the passenger car engines of the '60's and later. They rev higher, emissions and mileage weren't a concern- most weren't originally designed to run on lower compression ratios and no lead gas. So a surer, stronger spark was needed. The points and condenser wouldn't be able to keep up, especially above, say 4000 RPM as ignition quality degrades at those speeds with old-timey ignition.
The V-6, however is not that sort of engine. As a lugger, it winds out to top end at an engine speed my company minivan gets to for a slightly quick freeway entry. With a top end of 34-3800 RPM, the degradation of the ignition quality with points is negligible at worst. There's also that low compression which makes one wonder if it will burn anything this side of kerosene with some massaging. The thing was designed at the outset to run lean and on not the best fuel. Now, if I were running a '69 C20 with a 350 or 396, I'd definitely be looking at HEI.
I'm not totally against switching from points. I run a German Bosch 009 with Compufire in the '64 Karmann Ghia. It's quite nice and maintenance free (and I keep a set of points in the glovebox!). It works wonderfully with the 40 HP 1200 motor. I'm glad I did it.
The HEI has its advantages in any vehicle. Instantaneous starting. No maintenance- just check the timing when you change plugs. With a carb and points you have to bump the key a time or few- and a bit of fussing with a tune up.
I conclude that if your old dizzy is toast, go for HEI in a V6. A new old style one ain't cheap- like $250 at NAPA. If you throw in a new set of wires, you are mighty close to the custom eBay HEI.