HEI distributor - The 1947 - Present Chevrolet & GMC Truck Message Board Network

mudman · 12-27-2002, 01:04 AM

I want to upgrade my Distributor because my vacuum advance is bad on my points dist. Will all early gm distributors work. I have a small block chevy. Are all small blocks the same? Also what plug wires do I need and does the gap increase on the plugs?

thanks

**BIG ORANGE** · 12-27-2002, 01:13 AM

Excel makes good wire's atleast I've had good luck with them and the plug gap will need to be at 45,hope this helps!

72K10 · 12-27-2002, 07:17 AM

Hey, mudman! How's Sioux Falls? My brother lives there, and also my best buddy (well, he's deployed to Kuwait(?) right now, but he's got a guaranteed return assignment there). Anyway, if you're going to upgrade to HEI, then you should know that Chevy small block HEIs are all the same; will fit any small block chevy. You just have to decide if you want a Summit, a stock GM, NAPA, etc. Or do it the easy, cheap way and find a "donor" chevy car or pickup in the late 70s or 80s. You'll probably stick in R45TS plugs, which you can gap at .045. This increased gap gives you better fire in the hole. You do have to change plug wires, though, as HEI wires differ from your original. It's a straight swap except you need to run a straight wire from an unfused ignition slot on your fuse box to the BAT terminal on the HEI. Hope this helps.

GMC Jim · 12-27-2002, 08:25 AM

I bought my H.E.I fro a shop that specializes in disributor re-builds for standard and custon applications... I was advised that any distributor be calibrated to the advance curves as stated by the manufaturer and the application... Centrifugal advance weights and springs were selected to achieve the factory design specs. In my case, for a 402 engine; the following specs applied. O degrees @ 930 RPM; 2 degrees @1260 RPM; 16 degrees @ 2400 and 30 degree @ 4400 RPM..... A new vacuum advance was installed also; ( 20 degrees @ 17" hg. )...... I also regapped the plugs to .45 as suggested by the rebuider...... Have been very pleased with this ignition improvement and gas mileage, overall performance has been noticeably improved....... These distributors specs are kisted in the GM fatory Service Manuals

12-27-2002, 01:04 AM	#1
mudman Registered User Join Date: Nov 2002 Posts: 41	HEI distributor I want to upgrade my Distributor because my vacuum advance is bad on my points dist. Will all early gm distributors work. I have a small block chevy. Are all small blocks the same? Also what plug wires do I need and does the gap increase on the plugs? thanks

12-27-2002, 01:13 AM	#2
BIG ORANGE Senior Member Join Date: Oct 2001 Location: Lancaster S.C. Posts: 4,754	Excel makes good wire's atleast I've had good luck with them and the plug gap will need to be at 45,hope this helps! __________________ Things happen for a reason!

12-27-2002, 07:17 AM	#3
72K10 Registered User Join Date: Dec 1999 Location: New York Posts: 288	Hey, mudman! How's Sioux Falls? My brother lives there, and also my best buddy (well, he's deployed to Kuwait(?) right now, but he's got a guaranteed return assignment there). Anyway, if you're going to upgrade to HEI, then you should know that Chevy small block HEIs are all the same; will fit any small block chevy. You just have to decide if you want a Summit, a stock GM, NAPA, etc. Or do it the easy, cheap way and find a "donor" chevy car or pickup in the late 70s or 80s. You'll probably stick in R45TS plugs, which you can gap at .045. This increased gap gives you better fire in the hole. You do have to change plug wires, though, as HEI wires differ from your original. It's a straight swap except you need to run a straight wire from an unfused ignition slot on your fuse box to the BAT terminal on the HEI. Hope this helps. __________________ RLTW 70C10 72K10 72K10 Cheyenne 72C10 Cheyenne Super

12-27-2002, 08:25 AM	#4
GMC Jim Senior Member Join Date: Dec 2002 Location: Portland, Oregon Posts: 901	I bought my H.E.I fro a shop that specializes in disributor re-builds for standard and custon applications... I was advised that any distributor be calibrated to the advance curves as stated by the manufaturer and the application... Centrifugal advance weights and springs were selected to achieve the factory design specs. In my case, for a 402 engine; the following specs applied. O degrees @ 930 RPM; 2 degrees @1260 RPM; 16 degrees @ 2400 and 30 degree @ 4400 RPM..... A new vacuum advance was installed also; ( 20 degrees @ 17" hg. )...... I also regapped the plugs to .45 as suggested by the rebuider...... Have been very pleased with this ignition improvement and gas mileage, overall performance has been noticeably improved....... These distributors specs are kisted in the GM fatory Service Manuals __________________ '71 GMC;fleetside;PB/PS/AC/CC/402 Eng./Custom Paint/110,000act miles/3 fuel tanks(52gal).



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