Here's my combo: LS2, L92 heads, 595/598 232/234 112 cam, A1000 pump, 93 oct., 850cfm carb 30* timing pulling 6* down to 24* with 150 shot plate. Timing on all 7 cyl. looks right but #8 cyl. burns the ground strap off. Any ideals why only the one??? Thanks Rod

Forgot TR6 plugs gaped at 34

 

What plate and intake are you using? Any port work done to the manifold? Whats the compression of the motor, im thinking you need a colder plug then TR6 right off the bat. I would try to find the root of the problem before you start messing with the number 8 plug. What do the plugs look like NA? Some options that could work would be using some index washers to pull the plug out of the hole a bit. Could also try running a colder plug in that cylinder, but i would use that as your last resort.

 

Pull 2 more degrees out and see what happens with the ET or power wise, not sure what you're doing or just playing on the street. Maybe close the gap a bit to .030". Add more octane when spraying...colder plug as mentioned...what compression is this?

 

30 NA seems a little high me. Alot of people only run 28 NA.

 

To much timming and t hot of a plug. try 7's and 22 dergees for the 150 and post the pics of plugs. and by timming looks great what d you mean. most guys idea f timing based on na na lugs is wrong on the juice if you can see a timming mark theres 1 degree to much in it....

 

You need colder plugs. Find the plug with the shortest ground strap as well. If you still have issues then more octane may be needed. Also would not hurt to have the fuel injectors tested for flow. Is #8 injector not flowing the same as the others? If so then a good injector cleaning may help solve the issue. The weaker injector would not show up when running N/A as the demand on the fuel system is lower.

 

First thanks for the comebacks. I can't show the plugs now as I used (7) of them to make two more runs on motor. The timing mark is just below the curve and the fuel looks to be a little fat. This is a GMPP stock carbed intake with 850 Holley carb and an Edelbrock (spelling) plate under it. All testing was done at the track (1/4 mile). As far as the compression I would have to guess 10.5/1, stock is 10.9/1 and I changed the heads to the larger chamber L92s. It seems as though I need to go to the 7s from what yall are saying I do know they won't go as deep in the hole as the 5s (NA) and 6s I tried. I used the TR6s because of looking at what most on here are posting they are using with 150 shot. As for as the timing the car only makes about 3rwhp more at 30* than 28* doesn't seem to make much of a difference. I use 2* per 50hp as a starting place only. There is no port work done to any of this combo. This statement is new to me (if you can see a timming mark theres 1 degree to much in it.... ). And this one is the one I'm looking for (I would try to find the root of the problem before you start messing with the number 8 plug. ). I think I answered all, any more ideals? Once again thanks for all help. Rod

P.S. all N/A 11.46 118mph after nos pass 11.54 to 11.58 116 to 117 all other times

Here's what your working with

 

Give up the 3hp and start at 28*

If the plugs look rich the more you lean it out the lower the timing will need to be.
I think its a good idea what someone said earlier about running a colder plug in #7 & 8.
I wish we could do that but we are running TR11's already, so we pull timing out of those holes(with FAST XFI).

If its burning the tip off then its a good ways off. You need to go a far in the other direction and work your way back.