Here's how I put an HEI Distributor in my 1952 Chevy 216. I'm sure it would be the same for the 235 or 262. And obviously for other year Chevys 1949, 1950, 1952, 1953, 1954, 1949-1954. You can find an HEI distributor which fits a Chevy 250 on eBay for around $65. Search for Chevy 250 distributor or find one at a parts store for a 1980 Chevy truck with a 250. You can also find these modified to fit on eBay for 2 times the cost. You can save $65 by modifying it yourself. This is a very easy upgrade and doesn't require any machine work. All the modifications to the distributor to get it to fit can be accomplished with an angle grinder. Figure 1 below shows the original 216 distributor and the modified HEI distributor. As you can see the drive gear is nearly identical. To get it to fit you need to shorten the oil pump drive, relocate the hold down tab, and that's pretty much it. Figure 1: Original 216 Distributor and Unmodified HEI Distributor To correct the length of the oil pump drive I measured from the top of the drive gear to the bottom of the oil pump drive on the original distributor, see Figure 2: Figure 2: Measurement, Top of Drive Gear to Bottom of Oil Pump Drive, Original 216 Distributor You can see that the oil pump drive is about 0.25 in. longer on the HEI distributor, see Figure 3. I took my cut off wheel and removed the excess material until the measurement matched up with my original; about 2.75 in. from the top of the drive gear to the bottom of the oil pump drive. Figure 3: Measurement, Top of Drive Gear to Bottom of Oil Pump Drive, Unmodified HEI Distributor Next I ground off the original hold down tab. I used my angle grinder to remove most of the material, then cleaned it up with a file and a die grinder, see Figure 4. Figure 4: HEI Distributor with Hold Down Tab Remove For the new hold down tab I bought a split shaft collar from my local hardware store. The shaft collar has an ID of 1 in. The distributor housing shaft was slightly less than 1 in., around 0.95. To get a smaller radius on the shaft collar I compressed it slightly in a shop press, see Figure 5. This made for a perfect fit. Figure 5: Squishing the 1 in. Split Shaft Collar to Fit. To locate the new tab I measure from the bottom of the hold down tab to the bottom of the oil pump drive on the old distributor which comes to 4 and 15/16 in. I then located the split shaft collar on the HEI distributor measuring from the bottom of the collar to the bottom of the oil pump drive. I also checked it by installing the distributor without the collar attached, attached the collar, removed the distributor, and then checked the measurement. Using this method gave me 5 in. By going with 4 and 15/16 in. made me confident that when the distributor was secured, the oil pump drive of the distributor wouldn't be pressing on or binding the oil pump drive of the oil pump. Figure 6 shows the split ring collar installed (the new hold down tab) on the HEI distributor. Figure 6: Modified HEI Distributor with Split Ring Shaft Collar Installed When installing the new HEI distributor you can clock it where ever you want. I tried several positions but found that the one shown in Figure 7 worked the best. It provided plenty of room for the vacuum advance pod and rotation of the distributor to set the timing. Figure 7: HEI Distributor Clocking To clamp the distributor I bought a new hold down at O'Reilly's, hard to see but in Figure 8. Figure 8: Distributor Hold Down O'Reilly's also sells the pig tail connector for the 12 V and tachometer connection on the distributor. If you wanted to save a few $ you can just use a spade connector. The vacuum advance was hooked up with a rubber line from the original metal line. You'll need to change the distributor end spark plug wire connections. At first I Frankensteined together two old sets of wires. It wasn't long before I went ahead and just replace the wires with new ones. I also gapped my plugs to 0.45 in., might as well replace them while they're out. I used original part number plugs. Last thing to do is set the timing. Before making any adjustment, first remove and plug the vacuum line to the distributor. I set my timing to 5 degrees before TDC. When you hook the vacuum line back up your timming should jump. Depending on the advance of your can, you man need to switch out your can (if not adjustable) or adjust it to match factory settings. You also need to check your mechanical advance. I referanced Old Car Manual Project for the factory settings: https://docs.google.com/open?id=0B29e7ApG_niNUldnaGFwLWFEaDQ I've been running mine for several months without any problems. Since the install I can say my 216 has been running stronger, though I did replace the entire ignition system and adjusted the valves. Figure 9 shows a pic of the HEI distributor installed, it's a monster compared to original one. Figure 9: HEI Distributor Installed in a 1952 Chevy 216 For additional reference, here's a great write-up on tuning an HEI distributor. Web: http://www.73-87.com/7387garage/drivetrain/hei.htm PDF: https://docs.google.com/open?id=0B29e7ApG_niNSWhnRldLTndTZ2l2U1pnSU11d2E5Zw One last thing, you need to have a 12 V charging system. I did the HEI distributor as part of a 6 to 12 V conversion. If I missed anything feel free to add or let me know. If you want an easy to print PDF copy of this write-up you can get one here: https://docs.google.com/open?id=0B29e7ApG_niNYnRzSzF4aGhRUjZ1RnVsOXQ4V000UQ UPDATE -- Make sure you are using the correct gear on your distributor. Cast gear with cast iron camshaft and a steel gear with a forged steel camshaft. Check out Langdon's for a great description: http://www.langdonsstovebolt.com/tech/camshaft-cast-iron-or-steel-how-to-tell/ Hussey [email protected]
Nice tech piece .Any idea on how much better it runs .Hp increase or performance ? Is it worth the effort ?
I don't think you'd really get any hp increase. I think the greatest benefit is an increase in reliablilty and not having to mess with the points anymore. Mine was running ok before I did the conversion but it was probably in need of a tune-up to. After replacing the distributor, plugs, and adjusting the valves it was running alot stronger. Definitely worth the effort, talking 100 bucks for the distributor and a decent set of wires, and a Saturday afternoon, not much effort.
My 8 year old upgraded my Panel when he was 5. Watch for oil leaks around the distributor shaft. Try putting an O-ring around the shaft
Hey, I guess great minds (or somewhat decent minds) think alike. I saw an HEI in a guys 235 he talked it up like he custom machined it to fit. I searched but never found your post but found one on Chevytalk that give a brief description. Probably the easiest mod I've done.<O</O <O</O I haven’t had any trouble with an oil leaks but I'll have to keep an eye on it. The split collar give a good surface area for a regular distributor gasket to seal to. An o-ring would be a good solution, or spreading some atv sealant on there. <O</O
I know that this is an old thread, but I have just completed this conversion and installation. Everything went great thanks to your instructions. Engine cranks and runs great. I did have 1 question when it came to the vacuum advance hookup. Should the advance be hooked to the original stovebolt location at the carb or should it be hooked up to the manifold vacuum? thanks, Hugh
Cool, glad I could help. As far as the vacuum I just used the metal line that was alread run to the distributor, made it easy, I just had to put on a short piece of rubber hose on it. I know that line has vacuum at idle because when I hooked it up the timming jumps.
Nice looking '52. I have a '51 that is about the same color minus the flames. The vacuum line on my 235 goes into the bottom of the carb and does not have any vacuum at idle. I guess I will just try it both ways and see which runs the best. Hugh
I know this a old thread, but I was wondering if the dipstick tube got in the way of the vacuum can on the dist? I am doing this conversion and seems to be little room for timing adjustment.
Yes, timming was definitely tight but you if you "run out of room" to move the distributor you can pull it and move it a gear over. Doesn't matter which position it is in as long as the cap lines up with the rotor correctly. I think the best position I found was shown above in pic #7.
Thank you. I did install it like you did, but I had to remove the dipstick tube and roll a bend in it with a Rigid tubing bender to get full movement. I also had to weld up the back of the Wayne cover due to when I machined it for clearance. Hopefully I can finish the cover tomorrow, and see how it runs.
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