59 245hp spark plugs

[Robert D.]

what are the proper plugs for a 59 245hp (2 4 barrels) ive read r44 and r43s
thanx bob

[Donald L.]

Re: 59 245hp spark plugs

According to the manuel "Corvettes Technically Speaking" all 59 Corvettes used
AC 46 .

[Dave S.]

Re: 59 245hp spark plugs

The 1959 owners manual calls for all 59 cars to use AC46 for city driving and AC 44 for town and country driving. Also AC C43 COM for heavy duty and high output and AC C42-1 COM for extended and extreme high output. Plug gap
.033"-.038". I'd use 46's in and FI car and 44's or 45's in all others.

[Duke W.]

Re: 59 245hp spark plugs

Most long time small block owners agree that regardless of HP rating, the AC 45 is the best all around heat range for normal driving, but AC has deleted this non-resistor plug from stock.

The current alternate is the AC R45, a resistor type. You could also run the extended tip verion - R45S, NGK and Denso offer
a non-resistor equivalent to the 45, B4 and W14-U respectively and Denso's W14P-U is equivalent to the out-of-production 45S.

There is anecdotal evidence that extended tip plugs can interfere with the domes on SHP engines, but if your 283/245 has OE or equivalent pistons, they do not have domes.

Duke