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| | | Forums66 Topics128,012 Posts1,055,318 Members48,419 | | Most Online14,466 Apr 26th, 2026 | | AD Chevy Trucks Over 6,000 pictures Brad Allen has an awesome collection of Chevrolet factory pictures that he has set up from film strips. Check them out!
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on the Internet for over 30 years! and not clogged down with Ads! Again, thanks! | | | | Joined: Jul 2010 Posts: 89 Wrench Fetcher | | Wrench Fetcher Joined: Jul 2010 Posts: 89 | 'Morn All, Looking to get rid of points ign and replace w/HEI on my sb350 (pretty stock -mild cam)in my '51. I'm thinking of ordering this one but would appreciate someone's opinion as to whether or not this is the correct unit for my application. http://cgi.ebay.com/ebaymotors/SBC-...34?pt=Motors_Car_Truck_Parts_AccessoriesThanks Oh, it's a '71 block if that makes a diff does 65kv present a problem - too hot??
Last edited by Krash; 08/10/2010 2:46 PM.
it ain't YOURS 'till it ain't stock!
1951 chevy 3100
| | | | | Joined: Nov 2005 Posts: 238 Shop Shark | | Shop Shark Joined: Nov 2005 Posts: 238 | That'll fit into your SBC OK, just make sure you have enough clearance to the firewall so that you can slot in the bigger HEI unit.
Use bigger plug gaps with the HEI .040"-.050". Also I believe that GM recommended resistor style spark plugs with HEIs, although some people don't fit them and the system still seems to work.
Stuart. | | | | | Joined: Jul 2010 Posts: 89 Wrench Fetcher | | Wrench Fetcher Joined: Jul 2010 Posts: 89 | Seem to remember something about how many wires the hei unit has (module maybe) but can't rememberwhat was what. Anybody know?
it ain't YOURS 'till it ain't stock!
1951 chevy 3100
| | | | | Joined: Nov 2005 Posts: 238 Shop Shark | | Shop Shark Joined: Nov 2005 Posts: 238 | The early type HEI like the one in the ebay listing you linked to has two connections only; +12V and Tacho.
As well as these connections on the cap, the later "computer" type HEI has a multi plug from the module which goes to the engine management unit. These HEIs don't have the vacuum can which is clearly visible in the ebay photo.
Stuart. | | | | | Joined: Jun 2010 Posts: 188 Shop Shark | | Shop Shark Joined: Jun 2010 Posts: 188 | Definetly go with the skip white HEI. Awesome deal. Super delivery time too!! Likely 3 or 4 days for you. Don't forget to run a 10 or 12 gauge wire from a hot while key is on location too. Hei needs a full 12 volts to run. No resistor wires. | | | | | Joined: Jul 2010 Posts: 89 Wrench Fetcher | | Wrench Fetcher Joined: Jul 2010 Posts: 89 | Thanks for the confirmation gang. just wanted to make sure before placeing order - returns are less than fun.
No more matchbooks for me!
it ain't YOURS 'till it ain't stock!
1951 chevy 3100
| | | | | Joined: Jun 2005 Posts: 1,756 Shop Shark | | Shop Shark Joined: Jun 2005 Posts: 1,756 | Wish I had seen that before buying mine, Looks like a great deal. You might note if it doesn't fit you might have totake the gear off the bottom and replace it with your old one. I did. | | | | | Joined: Jul 2010 Posts: 89 Wrench Fetcher | | Wrench Fetcher Joined: Jul 2010 Posts: 89 | OK ya got my attention. why do you think you had problems with the gear and had to put your old gear on the new dist???
Last edited by Krash; 08/10/2010 11:15 PM.
it ain't YOURS 'till it ain't stock!
1951 chevy 3100
| | | | | Joined: Feb 2000 Posts: 5,191 'Bolter | | 'Bolter Joined: Feb 2000 Posts: 5,191 | Dad has one of the new HEI's for a Pontiac. Its a nice piece and works great, but there are some differences from the stock ones. The shaft is bigger diameter so stock gears won't fit, and something was different inside, but I can't remember what he told me. Its nothing to worry about, they had to change something to get around GM's legal department. His never missed a beat up to 6500 rpm on our distributor machine, it might even go higher, but thats the max rpm the old machine runs.
Joe | | | | | Joined: Jun 2005 Posts: 1,756 Shop Shark | | Shop Shark Joined: Jun 2005 Posts: 1,756 | Because it wouldn't drop in all the way. Missed by about3/8 inch. You could visibly see the new one was different. | | | | | Joined: Jul 2010 Posts: 89 Wrench Fetcher | | Wrench Fetcher Joined: Jul 2010 Posts: 89 | sounds like the oil pump wasn't lined up properly. anybody else experience this. never heard of the drive gears being different (how so?).
Thanks for the heads-up!
Last edited by Krash; 08/11/2010 2:39 PM.
it ain't YOURS 'till it ain't stock!
1951 chevy 3100
| | | | | Joined: Jun 2010 Posts: 188 Shop Shark | | Shop Shark Joined: Jun 2010 Posts: 188 | Only diffy would be what the gear is made of. There were bronze ones IIRC for use on roller cams I think. Memory a bit fuzzy!! I've never seen or had a problem with fitment. | | | | | Joined: Jun 2004 Posts: 8,597 Riding in the Passing Lane | | Riding in the Passing Lane Joined: Jun 2004 Posts: 8,597 | Bump the starter a bit or turn the engine by hand it will drop down when the slots line up. They say money can't buy happiness. It can buy old Chevy trucks though. Same thing. 1972 Chevy c10 Cheyenne SuperIn the Gallery Forum | | | | | Joined: Jun 2005 Posts: 1,756 Shop Shark | | Shop Shark Joined: Jun 2005 Posts: 1,756 | Hey Crash, all I know was the gears were different When I went thru auto shop a million of years ago the instructor used to take the distributor out of a engine and then spin the engine over to see if we could get it right. SO I have been there and done that. | | | | | Joined: Jul 2010 Posts: 89 Wrench Fetcher | | Wrench Fetcher Joined: Jul 2010 Posts: 89 | Well, just ordered one. Guess I'll find out in a few days. Thanks for the comments and advice,gang. Tom
it ain't YOURS 'till it ain't stock!
1951 chevy 3100
| | | | | Joined: Jul 2010 Posts: 89 Wrench Fetcher | | Wrench Fetcher Joined: Jul 2010 Posts: 89 | bought it installed it much better than before easier start for sure. runs stronger as well. priced the accel wires that come with and that alone makes the deal worth it.
box said adj vac adv - even came w/ allen wrench but dosen't feel like the allen wrench enguages into anything in the port. how easy does the adjuster turn w/ the allen wrench? - no resistance? some? ??
Little worried about the seller though. glad there were no porbs. email is ubdeliverable, 1-877 number no good. Hummm...
it ain't YOURS 'till it ain't stock!
1951 chevy 3100
| | | | | Joined: Feb 2000 Posts: 5,191 'Bolter | | 'Bolter Joined: Feb 2000 Posts: 5,191 | Since the vacuum is only 14 to 20 inches, the screw is probalbly pretty easy to turn.
Joe | | | | | Joined: Jul 2010 Posts: 89 Wrench Fetcher | | Wrench Fetcher Joined: Jul 2010 Posts: 89 | thanks i'll have to tinker with it more this weekend.
it ain't YOURS 'till it ain't stock!
1951 chevy 3100
| | | | | Joined: Feb 2004 Posts: 29,743 Kettle Custodian (pot stirrer) | | Kettle Custodian (pot stirrer) Joined: Feb 2004 Posts: 29,743 | Can you feel the Allen wrench making its way into the adjuster? It's probably pretty deep into the chamber, about midway, where the diaphragm would be. The function of the adjuster will be to limit the total travel of the advance unit to set how much vacuum advance you get. The only time there would be much resistance to turning would be when the travel is bottomed out, engine running and vacuum applied. At that point, the adjuster won't be accessible because the vacuum line will be attached.
Try checking the advance with a delay-flash timing light at 2,000 RPM with the advance disconnected, then connected. The difference in timing will be how much the vacuum advance moves. Adjust it up or down for best performance and fuel economy. Most vacuum chambers advance the timing 8-10 degrees at light-throttle cruise. Don't exceed about 40-42 degrees total advance with initial, centrifugal, and vacuum all maxed out. Jerry
Last edited by Hotrod Lincoln; 08/20/2010 1:19 PM.
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| | | | | Joined: Jul 2010 Posts: 89 Wrench Fetcher | | Wrench Fetcher Joined: Jul 2010 Posts: 89 | lincoln thanks for the specs don't know why i couldnt feel the engaugement while distributor was out but can now. crane cams also has instructions with their adj vacc adv unit. i'll be 'dialing it in' this weekend. thanks
it ain't YOURS 'till it ain't stock!
1951 chevy 3100
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