Did my Mini HEI install a few days ago. After sorting out my carb issue I moved onto something new. Previous setup was a Pertronix system that worked fine. Worried about something busting and not finding parts easily is why i really wanted to change to HEI. The unit I got was from Tom L. Install was straight forward and only took about an hour.
Before starting I made notes and observations on how the truck was setup with the Pertronix. I was running the timing at 10 deg and all is running smooth and power is there at the mid to high rpms. Starting was easy and idle seemed smooth at 500rpm. Truck would hold this faily close with the dash tach and the timing light tack slightly bouncing by about 10ish rpm. Pertronix coil would always get super hot and the stock dizzy had the slightest wobble to it as it would rotate (kinda funny to watch) The spark plugswere gapped to .038 and are NJK BR9ES.
First thing i did was find my #1 tdc and that was easy as i marked my distributer before and made sure down was #1.
Next was to remove the old distributer and old coil. I made a fast bracket to hold the new coil. Will make another one soon with hidden bolts, solid bends and chrome finish. The bowtie alone adds 5 hp.
Installed the new coil and distributer. Next was to change over the wire ends so they would attach to the new coil tabs. Once that was done the coil was rotated and positioned as required so the pickups would line up. The unit was then bolted in. The old plugs were removed and the new ones installed. All gaps were checked and all came in at .060.
After that is was a simple 5 min to install the cap and the new wires Ialso got from tom. The reason i got new wires was so i could do the swap quickly and not have to redo the ends on my current 8mm wires to fit the new cap. The new Black wires are also 8mm. I will now change over the ends on my existing blue ones and reinstall them one day.
The truck was fired up after that with no issues. First thing i checked was the timing. I wanted to see if any possible changes would arise from this install so I once again set the timing to 10deg. First thing i noticed right after doing the timing was the truck idled higher. The rpms went up by about 70. After going back and forth between the idle speed screws and ensuring the mechanical timing still kept it at 12 deg. i got it back to 500rpm.
First observation was the engine was smoother than before and much quieter. Just the ticking of the valves and the slight exhaust note. The rpm was holding considerably more stable and not fluctuating nearly as much. Rpm would bounce only about 4rpm on the digital timing light readout. . The dash tach was also rock steady and not fluctuating.
The stationary revving of the engine sounded the same and nothing was noticed at that time. Got in the truck and went for a boot. Left the crescent cautious as i just wanted to ensure nothing would advance under hard load or such and cause issues. Just taking off alone in first seemed smoother and seemed to take less pedal. After getting it out to an open road and cruising at 40 mph I hit it all the way. I was absolutely blown away how this thing would accelerate now, in no time I was at 60mph. Being in second or third around the 2000ish torque curve and mashing it was just unreal compared to the way it was before. Even taking it down the highway now at 3000 rpms (60mph) its smoother and not as loud.
I can go on and on about how much better it runs and how much more power it has but im not going to blab and blab. Maybe its because the better spark now, or possibly the mechanical and vacuum advance has a slightly different curve. Whatever it is I’m super happy with it. If I had a group of local club or forumn guys I would let them all try the truck and take an hour and install the old ignition back and let them see for themselves. I would put my truck on it that it made a huge difference and I know others after a test would agree.
I will try advancing the timing a bit here and there and see how it changes things
Little video I took today. Sorry about the muffled sound. Could have gone harder but was not sure who might have been lurking above the hill lol. Truck actually starved itself when I hit 70mph at 4000 rpms. I need to really change my gearing.
Nice writeup. The two threads on HEI is making a compelling argument for swapping away from points. I guess I'm one of the few that hasn't been stranded by bad points/condenser so I'm in no hurry to change. That said I do like hearing how HEI improves performance, as that is something I'm always interested in improving.
Couldn't help but notice in your vid how easy the steering was. I'm still OEM stock and the "power" in my steering is me If I hadn't lost alittle weight I doubt I could have fit behind my OEM steering wheel You may have posted it before but I would be interested in learning more about your PS setup.
