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post #1 of (permalink) Old 09-04-2000, 06:22 PM
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HEI in a 87YJ?

Will a HEI ingition work in the 87YJ. What else needs to be done. What about the computer, will it still work?

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post #2 of (permalink) Old 09-04-2000, 07:45 PM
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Re: HEI in a 87YJ?

I put an HEI in my '89 YJ with the 258. Going with the Ford TFI upgrade would be cheaper, easier, and more reliable...but I didn't know about it back then and I think the HEI is much better for running underwater.

You need to get a HEI distributor from a Chevy 250 I-6 engine. I got mine out of a '78 Nova. Replace the driven gear on the bottom with a driven gear from an AMC V-8 (304, 360, etc...) and replace the standard parts like cap, rotor, coil, wires, weights, etc. You may also want to chip in for an adjustable vacuum advance for more tune-ability. Installing it is like installing any other distributor, here is instructions on what to do: http://www.geocities.com/sycho15_2000/ignition_woes.htm. The only wire you will need to hook back up is the black one.

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post #3 of (permalink) Old 09-04-2000, 09:10 PM
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Re: HEI in a 87YJ?

First of all, I'm assuming you have the AMC 258 I-6 engine....?...
You gave no details, and you didn't fill out your bio, so there is no way for us to tell what engine you have, and there is a HUGE difference between the I-6 and V-8 conversions or upgrades...

Actually, to do the GM HEI CONVERSION (conversion, not upgrade...) correctly, you will have to install a power relay, or you are wasting time and money.
The GM HEI is a power hog, and you are severely limiting the potential of the GM HEI if you don't supply it with a 10 Ga. wire supply, and no ignition wire in your stock ignition system is 10 Ga., so you will have to wire from scratch, or install a relay.
Done correctly, it's far from a "One Wire Install"....

The Ford upgrade is more powerful, more reliable, and more water tight if done correctly, and it's a lot easier and cheaper to do that the GM HEI conversion, and it won't interfere with your 'computer' or on board emissions systems.

If you decide to go with the GM HEI, get one from about a '76 Chevy I-6 pickup that has the remote coil, so you get the ignition coil out of the cap.
(Yes, there is such an animal, and it uses a properly designed E-core coil)

Use a premium cap and rotor with brass terminals, and reasonable plug wires...

If you want the alternative to the GM HEI, let me know and I'll re post the upgrade article again for your stock ignition. I will need to know if you have a V-8 or I-6.

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