602 crate spark plugs

[hsracer]

Whats the difference in the NGK V-POWER TR-5 and TR-55. In the crate paper you get from gm when you buy the motor they say NGK TR-5 but I see racers using TR-55. I have a set of TR-5 in the motor now. Will it hurt the motor or should i get different plugs. We have to run on 94 octane pump gas only no racing fuel. Carb is a Holley 2 barrel 500cfm

[rubbinsracin]

i might be wrong, but i think they are basically the same plug. JEGS website has them as basically the same thing, only difference i can see is that one is that the 55 is is gapped at .059" and the 5 does not have a gap specification. both have same reach of .708"

personally i put the 5's in because thats what the paper said. i guess you could go out and buy one 55 and one 5 and see what the difference is.

http://www.jegs.com/i/NGK-Spark-Plug...oductId=753971

http://www.jegs.com/i/NGK%20Spark%20...0002/-1?CT=999

[hsracer]

Ok thanks for the information i found the same thing about the gapping for 5's and the 55's.

[swaybar]

I believe they are the same plug with the exception of the heat range. the TR55 is a little colder than the TR5.