1976 Fleetwood Brougham Tune Up Question

[dannygila]

Hello,
I would like to do a tune up on my 1976 Fleetwood with the 500ci. Does anyone have any recommendations as to which spark plugs (and brand) would be best to use? I see there are copper ones, platinum, iridium, double platinum, etc. Would going with ACDelco for everything (plugs, wires, cap, rotor, etc.) be the way to go? Thanks.
-Dan

["Cadillac Kid" Greg Surfas 15364]

I've found the best for my stock motors is exactly what the FSM calls for.
Spark Plugs:
https://www.rockauto.com/en/moreinfo.php?pk=90017&cc=1409374&pt=7212&jsn=492
Cap, rotor and wires AC Delco, although having been "cheapened up" over the last decade, are IMHO still adequate and will last for the recommended usage periods.
Greg Surfas

[TJ Hopland]

For sure I would stick with a standard copper plug which are darn near a special order part these days.  Parts stores only seem to stock the fancy ones even for old applications like this.  Brand I don't really think it makes much difference these days, any of the big ones AC, NGK, Champ, Autolite.

For wires I like the Belden ones that I think Napa sells.  I still like the Standard Ignition brand too. Cap and rotor again I like Standard Ignition especially their Blue Streak line.  Note that the caps and rotors for GM V8's were mostly the same so even though it may not be listed as fitting many of the hot rod brands work too like a MSD or Accell.  In the past I have got those kits off the hot rod self in the parts store for about the same price as the premium quality OE type ones that usually have to be special ordered.

While you are in there make sure your vacuum and mechanical advances are working. If you are going to change anything or take anything apart take 'before' timing readings at various RPM and vacuum settings.  Take pictures or notes so you can get back to known running settings.  Way too many horror stories of people that had a running engine then put things back to specs and they no longer ran.

Same goes for even if you are just changing wires.   Look for where #1 is now on the cap, it may not be where the factory put it.   Also remember this engine #1 is front on the passenger side which is different than most other American engines of this era.   

[dannygila]

Thank you very much for the input.

[J Kinley]

I am timing my 500 in my 1973 Eldorado.  Old distributor with pertronics ignition. I blocked off the vacuum advance,  set the timing at 8 degrees tdc at 600 rpm.  I unblocked the vacuum and the timing mark went to about high noon.  The rpms went to 950.  The engine sounds good. Is this normal?  How do I know if the  mechanical and vacuum advance is working right?
Thanks John

[The Tassie Devil(le)]

I am timing my 500 in my 1973 Eldorado.  Old distributor with pertronics ignition. I blocked off the vacuum advance,  set the timing at 8 degrees tdc at 600 rpm.  I unblocked the vacuum and the timing mark went to about high noon.  The rpms went to 950.  The engine sounds good. Is this normal?  How do I know if the  mechanical and vacuum advance is working right?
Thanks John

To check the mechanical advance, with the Vacuum still blocked off, and the timing light still attached, rev the engine to see what the distance the light moves towards the advance position on the balancer.

To check the Vacuum Advance, you will need an adjustable Timing Light and wind the adjuster to bring the timing mark back to zero, and then read how much you have wound it back on the timing light handle.

Another way is to pull the Distributor, and fit it to a Distributor Strobe machine and check it that way.

Bruce.

[J Kinley]

I found the instructions for my timing light and printed off a distributor curve from speedway motors.  I will see how well it's working tomorrow.
Thanks John