Have a 394 with 2 BL carb. Need to know what AC DELCO plugs # to put in it. 1962 Olds 88 .

 

My books show:
High compression: AC 44
Low compression: AC 45
The gap in either case is 0.030"
Torque: 35 ft.-pounds

 

AC 45 gapped to .030 according to Carnut.com which I trust.

http://www.carnut.com/specs/gen/olds60.html

AC R43S according to Fusick Olds which I both trust and have pleasantly dealt with.

http://www.fusickautomotiveproducts....s.asp?dept=703

Why the difference ? My guess is the R43S is the modern more readily available equivalent. As it does make the Carnut list but only as early as 1969 ...

I would still verify before proceeding.

 

The compression makes the difference. The lower the number, the colder the plug (unless NGK, they're the other way). A hot plug in a high compression engine will likely have detonation problems.

 

Use the 45 or other brand equivalent. If you get detonation on 93 octane then use the 44. The 43 is a cold plug which likely won't burn off deposits in normal driving.

There's a tech bulletin from 1965 addressing this. Recommends use of the 43 only in Starfire 394 engines regularly seeing high speed or hard acceleration service. Course there was 100 octane leaded fuel available back then too.

 

What color is the block? IF red it should be the hi compression engine, if turquoise it is probably the low compression. Either one could be had with a 2 bbl...Tedd