Quick Q. Tuning my new HC setup. 243 heads (10.7 to 1 compression). Noted that the car does NOT like lots of timing (ie abov 24 degrees WOT and a little less than stock values pat throttle. Anything more = knock.

Running TR55 plugs. These too hot? Thinking maybe I should go back to TR6's. $0.02 appreciated.

 

Go tr6

 

Autolite #5243 is a good starting point.

 

With high compression and a lot of timing retard, you probably want to close down the gap a bit too. OE spec is 0.060", maybe try 0.045" to make sure you stay clear of misfire.

 

A lot of guys go with the tr6 for hi compression

 

Thanks for the info Sounds like I'll be putting the TR6's back in.

 

on the TR6s

 

i went with a 7 range plug for n2o and im running a little more compression than you...I was having bad knock issues with the stock timing tables and the 6 range plug....I found stock ls6 timing tables and went with the colder plug and it eliminated my problem....high compression and pump gas = tuning

 

yep, what he said

 

Good info. I picked up some TR6's today. Family commitments kept me from installing them. Will do that tomorrow and see how she acts then

 

What gap are the current plugs at and how do they look after some WOT runs?

 

The TR55's got swapped today......

But, to answer your Q, they looked light grey and the electrodes were fine. There was a hint of brown on a couple of the ceramics by the electrode, thus confirming sporadic knock.

The TR55's were gapped to .050.

The TR6's I just installed are gapped to .035.

 

Same here Tr6

 

Alright, you should be fine with the Tr6's. I started running the 6's when I went over the 450 rwhp range.