I was doing some reading and claims are that gap depends on mods and horsepower. So what would be the proper gap for my NGK TR55's...

1999 Trans Am WS6 6 Speed
Stock LS6 Heads and Intake
Pacesetter Headers
Borla Exhaust
MSD 8.55MM Wires
SLP Lid + K&N Air Filter
228/232 112+5LSA Cam
Made 382rwp 390tq. Was tuned, but needs a bit better of a tune...

Also we only have access to 91 Octane Fuel here in Canada, if this makes any difference.


So once again, based on the info provided above what gap would be most benificial for the NGK TR55's in my car.

 

From what I've read and been told before by professionals , That the best spark plug gap for NA engines is at .050.

 

gap should be .050

 

Interesting - both GM and NGK think that plug should be gapped at 0.044".

 

.060.........thats my story and i am stikin 2 it

 

We typically gap them at .050. You shouldn't have a problem there.

Jon

 

Been gapping them at .050 for years .... works great.

 

Not sure if you realize it, but the second number denotes the gap. Check the NGK catalog. The TR5 and TR55 are exactly the same plug, but the TR55 has a wider gap. Why not just get the plug you need?

 

.050 is what i've seen

 

I have no doubt that the 0.050" works just fine, but I am still curious where the spec originates since GM doesn't use that spec and the plug manufacturer doesn't use that spec.