I want to upgrade my 69 Coupe with an HEI ignition. Does any body know what parts I need? can i get new parts or should i be looking for used parts?

Thanks

What size Motor? I have upgraded my 71 eldo 500, to a HEI off a 1979 425, I rebuilt a 425, and took out my 500 standard points, and coil, and distributor. Havent ran it yet, but real simple, just need a HEI distributor off a later model car. Get new resitor type plugs, and HEI Plug wires the connections are different. then wire to a 12v point on fuse box. I would know more if you had the motor size. Thanks

RE: HEI on 69 deville it has a 472ci.

If you have the greenbacks, you can get what you need from MSD for about $600 (new). With MSD you need the distributor and an ignition box. They only have the one model for Cadillac 472 and it requires their 6A box.

You can get a distributor from DUI Distributors for about $400. (That's what I did. I got the distributor for the Cadillac 472, new spark plug wires, and little electrical connector for the BAT terminal on the distributor.)

BUT you could do it way cheaper. There are lots of stories on this forum. You can get one from a junkyard from post 1975 472-Cadillacs (I think it's 1975 when they changed?) I read one success story by a guy who bought his HEI distributor on ebay. I think the tribal knowledge states that if you get a used or junkyard HEI, you should expect to do a little work on it to bring it up to speed. In the end I thought it was worth it to buy the DUI for the simplicity. It just needs one 12 volt wire. The coil is in the cap. You will need spark plug wires made to fit an HEI (they have the female ends like where the wires you have now connect to your spark plugs). I opted to pay $100 for a nice set. And like I said, I threw in a couple extra bucks for the connector for the 12V wire to the distributor. If you go the junkyard route, I am told you should snag this connector off the car you pull the distributor out of.

I guess another option for new is Pertronix. ANd they sell the stuff you might need to refurbish a used distributor. I suggest you read up on the subject a little (do search on HEI on this forum) and then call MSD, DUI, Pertronix. They will probably be helpful, at least i know the DUI guys were.

Oh yeah you will need new spark plugs with a larger gap, .050" to .060".

Dunno why anybody would need to spend a lot of money on an H.E.I. conversion unless it's for a highly modified engine. Find a dead 425 equipped car in the junkyard that had a recent tunup. Lots of "mechanics" tune up cars after the engine blows up in some way hoping to make it run again. Take all the stuff out and install it in your car. Certain older year Cadillac engines are far better off with their original mechanical and vacuum advance curves. IIRC, the H.E.I. mechanical and even some vacuum advance parts will swap with the older points distributors (I haven't had my hands on a Cadillac points distributor for 15 years and I was throwing it in the scrap metal pile then). You might want to consider leaving the entire curve as stock. If you do use all the new stuff then the vacuum line hookup must be changed to make it similar to what the later cars use. Distributor vacuum goes right to manifold instead of ported vacuum on the newer cars. Setting timing with the late parts is done according to the later car's proceedure. If you have one of the engines with the dished pistons the timing is very critical. I've found that 1972 is totally different from 1971 even though KM parts books say that the engine internals are all the same!
Any points equipped car will have a dropping resistor somewhere in the power connection to the coil. Cadillacs use a resistance wire. This wire gets bypassed right to 12 volts by the S terminal on the starter when cranking. The amount of voltage drop on the resistance wire is in direct proportion to the current load placed on it by the spark coil. The H.E.I. coil does not draw anywhere as much current as the old oil filled spark filled points type coil so the voltage drop is less. One can get away with simply leaving the resistance wire in place and feeding the B+ terminal of the H.E.I. with the same wire that used to feed the + side of the old spark coil. Plenty of conversions were done this way. Is it textbook right? No. You want to bypass that resistance wire so the textbook guys can sleep at night. I'd bet a lunch that the available secondary voltage from a 1977 425 H.E.I. setup varies less than 15 percent with the resistance wire from a 1971 472 in series with the B+
terminal.

Thanks for the good info, Ape Man. I think I'll stick with the "textbook" wiring approach for now, but if I continue to be plagued with difficulties with my wiring, maybe I'll just hook up the resistor wire and see if that works.

One thought about vacuum advance hooked straight to manifold vacuum. I have read that when you do this you should verify that you have the correct vacuum advance can. Again you would want to match the specs of the later vehicle. The key is to ensuring that the high vacuum at idle is enough to advance the timing all the way, maxed out. Otherwise you may get a loping idle. Whenever the hell I get mine running, I am planning to hook up the vacuum in the stock configuration, with a ported vacuum switch. Currently my vacuum lines are not hooked up correctly. The ported vacuum switch gives you manifold vacuum advance above 220*F and advance is controlled by carburetor vacuum below 220. Any thoughts on that?

Perryl, back to your original question, someone posted this link in another thread:

http://www.mtscadparts.com/

Download their catalog and price sheet, they have some lower cost options for you. Then I would call them and ask them specific questions about exactly what items you would need. For example, is it coil-in-cap, or do you need a separate ignition coil or box?

Thanks for the good info, Ape Man. I think I'll stick with the "textbook" wiring approach for now, but if I continue to be plagued with difficulties with my wiring, maybe I'll just hook up the resistor wire and see if that works.

One thought about vacuum advance hooked straight to manifold vacuum. I have read that when you do this you should verify that you have the correct vacuum advance can. Again you would want to match the specs of the later vehicle. The key is to ensuring that the high vacuum at idle is enough to advance the timing all the way, maxed out. Otherwise you may get a loping idle. Whenever the hell I get mine running, I am planning to hook up the vacuum in the stock configuration, with a ported vacuum switch. Currently my vacuum lines are not hooked up correctly. The ported vacuum switch gives you manifold vacuum advance above 220*F and advance is controlled by carburetor vacuum below 220. Any thoughts on that?

You want to make sure the vacuum advance is working and configured properly wheather it is hooked up the new or old way. A loping idle is usually from a lean condition and too much timing on these cars. Dunno if you got my point (no pun indended). The resistance wire can be left in place with an H.E.I. conversion. It should be removed but the world won't end.

Yeah, I got your point, and I'm glad to hear that it will work with the ballast wire because wiring the thing up was kicking my ass. (Though not as bad as just simply removing the old points-style distributor, if you recall that episode!) I think I have the wiring figured out thanks to help I have got right here. But I don't have a success story to share just yet.