Best NGK for hi-po 396?

[mockingbird812]

My search skills aren't working so well today as I know we have discussed this earlier. But, I need a recommendation on the NGK suited for my '69 L78 engine. Am running CR from factory and no mods to engine.

Thanks!

[Mr70]

NGK UR 5 #2771..Just bought a set for my #291 heads.
http://www.ebay.com/itm/Pack-of-4-New-NGK-Spark-Plug-UR-5-V-Power-Copper-Core-2771-Lot-of-4-NIP-/162548958207?epid=115129229&hash=item25d8ac43ff:g:UoAAAOSwNRdX~VaI&vxp=mtr

[VintageMusclecar]

That's the wrong plug, it takes a 5/8" socket. Sam's takes the early 13/16" socket--will have a PN in a moment...

*edit*

B6ES-11

BR5ES

BR6ES

[Mr70]

Ah true...1970 on my mind.
Here's a comprehensive list Rob Posted about 10 years ago that I've found to be more accurate then todays list.


Problem is, Delco doesn't make their plugs any more...simply repackages them...wanna say they're made by the same place that makes Champion plugs? The side cut Autolites work ok. When we messed with plugs on the dyno, my beloved AC's were horrible...no matter of the heat range, they all SUCKED...stuck in an NGK, and I've never looked back.

----------------------------------------------------------------

LT-1 with 186 heads:my AC book calls for a C43 or an R43 plug, and the NGK site says-

Standard, V-power (3/8" reach, 13/16" hex, projected tip, gasketed seat):
XR4 / 5858
XR5 / 3332

Race, V-power (3/8" reach, 5/8" hex, projected tip, gasketed seat):
R5670-6 / 4449
R5670-7 / 5034
R5670-8 / 5657
R5670-9 / 6468
R5670-10 / 6702

L72 with 840 heads:my AC book calls for a R44 or a 44N plug, and the NGK site says-

Standard, V-power (3/4" reach, 13/16" hex, projected tip, gasketed seat):
GR4 / 2635
GR5 / 2851

FR4 / 5155 (same as GR plugs, except for 5/8" hex)
FR5 / 7373 (same as GR plugs, except for 5/8" hex)

Race, V-power (3/4" reach, 5/8" hex, projected tip, gasketed seat):
R5672A-8 / 7173
R5672A-9 / 7405
R5672A-10 / 7942

R5671A-7 / 4091 (same as 5672, but with non-projected tip)
R5671A-8 / 4554 (same as 5672, but with non-projected tip)
R5671A-9 / 5238 (same as 5672, but with non-projected tip)
R5671A-10 / 5820 (same as 5672, but with non-projected tip)
R5671A-11 / 6596 (same as 5672, but with non-projected tip)

LS6 with 291 heads:my AC book calls for a R43T, and the NGK site says-

Standard, V-power (.460" reach, 5/8" hex, projected tip, tapered seat):

UR4 / 6630
UR5 / 2771
UR6 / 7773
YR5 / 7052 (same as UR plug except w/ non-projected tip)

Race, V-power (.460" reach, 5/8" hex, projected tip, tapered seat):

R5674-6 / 4449
R5674-7 / 5034
R5674-8 / 5657
R5674-9 / 6468
R5674-10 / 6702

R5673-6 / 2405 (same as 5674, except w/ non-projected tip)
R5673-7 / 2817 (same as 5674, except w/ non-projected tip)
R5673-8 / 3249 (same as 5674, except w/ non-projected tip)
R5673-9 / 3442 (same as 5674, except w/ non-projected tip)
R5673-10 / 4050 (same as 5674, except w/ non-projected tip)

[Salvatore]

Sam, there are a box of Holley Plugs on Ebay. Holley plug #25-31. They should work. If you can find 25-30, better yet!

25-57 and 25-41 are the projected tip. Been running the Holley's for years with good results.

[mockingbird812]

Good info guys. Thanks a bunch!!!!

[Mr. Chevy]

Sam, I use NGK plugs in all my old cars... They are awesome. Trouble is I put them in my stock L78 Nova motor so long ago I can't remember the part number but I'll get it for you...

Those plugs are so good that sometimes the L78 motor loads up from sitting and they clear out on their own...

Rich