What spark plug for a '65 327ci, 350 hp?

[Edward L.]

Any help, I know the AC Delco 44 is the correct plug but can't find it locally, any suggestions on a sub?
Thanks ED

[William C.]

Re: What spark plug for a '65 327ci, 350 hp?

Edward..There is a set of AC44 on EBAY for $40. I'm running R45 in my L79. They are 1 heat range hotter than 44's, but for normal driving there fine...Bill

[Edward L.]

Re: What spark plug for a '65 327ci, 350 hp?

Any other brands that would be equal the AC Delco 44?

[Jim T.]

Re: What spark plug for a '65 327ci, 350 hp?

I have used RJ12Y Champion spark plugs in my 68 327 350HP for over 30 years.

[Edward L.]

Re: What spark plug for a '65 327ci, 350 hp?

Is that run the same heat range as the 44?

[Jim T.]

Re: What spark plug for a '65 327ci, 350 hp?

Do not know about heat range, also use the same Champions in my 1970 350/300.

[Joe L.]

Re: What spark plug for a '65 327ci, 350 hp?

Is that run the same heat range as the 44?

Edward------


The RJ12YC (RJ12Y is no longer available) is equivalent to the AC R44S. The R44S is an extended tip version of the R44. I would highly recommend the Champion RJ12YC for your application.

If you want the exact equivalent of the R44, then use the Champion RJ8C.

[Louis T.]

Re: What spark plug for a '65 327ci, 350 hp?

Hi Edward,

I follow DukeMay 9th, 2011:



Even at high cruise speed, all Corvette engines are operating under relatively low load, so they can get away with relatively hot plugs that will stay clean in low speed driving.



Good luck,

Louis

[Dennis O.]

Re: What spark plug for a '65 327ci, 350 hp?

I agree with the Denso W14-U as well. I was having troubles with the AC R44S (extended tip resistor plugs) running too cold on my '67 L79 (When I pulled them, they were black, not brownish tan), so I switched to the Densos (non-resistor) and have been very happy. An additional advantage. I found them on eBay for $1.10 each (shipping included!). The prices for original AC 44's I found were ridiculous, and AC 45's seem to be made of unobtainium.

[Michael M.]

Re: What spark plug for a '65 327ci, 350 hp?

Edward, your choices are AC R 45TS, Bosch (old) WA 145 T30, Bosch (new) HR 8Y, Champion RBL 15Y, Fram/Autolite 415, Mopar P-62 PR, Motorcraft BRF-42, NGK BP 5ES-15, Nippondenso W 16 EP, and Prestolite 14GR 5 2A. The recommended heat range and what you use is up to you. Hope this helps.

[Joe L.]

Re: What spark plug for a '65 327ci, 350 hp?

Edward, your choices are AC R 45TS, Bosch (old) WA 145 T30, Bosch (new) HR 8Y, Champion RBL 15Y, Fram/Autolite 415, Mopar P-62 PR, Motorcraft BRF-42, NGK BP 5ES-15, Nippondenso W 16 EP, and Prestolite 14GR 5 2A. The recommended heat range and what you use is up to you. Hope this helps.

Michael-----


I believe that an AC R-45TS is an extended reach, TAPERED SEAT spark plug. If so, it won't work for a 1966 application which all used gasketed type plugs.

[Donald T.]

Re: What spark plug for a '65 327ci, 350 hp?

I've been running AC R45 in my 65 L79 for years and they are fine for normal driving. If you REALLY want the correct AC 44, they can be found occassionaly on ebay. Also, the AC R44 would be the resistor version of the same plug and they are cheaper and more plentiful on ebay.

[Stuart F.]

Re: What spark plug for a '65 327ci, 350 hp?

Being old school, I have been running the same set of AC 44's in my 63 L-76 SHP for the last 10 years. But, of course, we're only looking at maybe 6,000 or 7,000 miles, and it's not as if they age. The engine will still hit redline with ease if I don't "self impose" my 5500 RPM rev limit. I expect that is because of my Pertronix coinversion which has made frequent plug changes a thing of the past (for me). It is getting about time to make a change only because I am afraid they (the AC's) will rust into the heads. With this thread bringing up the subject, I went out to check my old stock and here's what I have;

(1) set AC45S "Fire Ring"

(1) set AC45 "Fire Ring"

(2) sets AC R43's

(2) sets Champion J-12-Y's

(1) set Champion N-12-Y

Now then, can anyone tell me which would be the better choice given the knowledge that my engine lives well with the AC44 heat range. Also, those N-12-Y plugs look suspiciously like "long reach" plugs for either a "W" engine or a big block - both of which I worked on a lot back in the day, but my old memory fails me and most of my 3" x 5" card records areonly about Carburetors and Distributors.

Stu Fox

[Joe L.]

Re: What spark plug for a '65 327ci, 350 hp?

Being old school, I have been running the same set of AC 44's in my 63 L-76 SHP for the last 10 years. But, of course, we're only looking at maybe 6,000 or 7,000 miles, and it's not as if they age. The engine will still hit redline with ease if I don't "self impose" my 5500 RPM rev limit. I expect that is because of my Pertronix coinversion which has made frequent plug changes a thing of the past (for me). It is getting about time to make a change only because I am afraid they (the AC's) will rust into the heads. With this thread bringing up the subject, I went out to check my old stock and here's what I have;

(1) set AC45S "Fire Ring"

(1) set AC45 "Fire Ring"

(2) sets AC R43's

(2) sets Champion J-12-Y's

(1) set Champion N-12-Y

Now then, can anyone tell me which would be the better choice given the knowledge that my engine lives well with the AC44 heat range. Also, those N-12-Y plugs look suspiciously like "long reach" plugs for either a "W" engine or a big block - both of which I worked on a lot back in the day, but my old memory fails me and most of my 3" x 5" card records areonly about Carburetors and Distributors.

Stu Fox

Stu------


The N12Y plugs are for big block applications, not small block.

[Timothy B.]

Re: What spark plug for a '65 327ci, 350 hp?

Stu,

If the color on the AC 44's looks good I would leave them..