I have a stock bottom end ls1 with 5.3 heads which should have my compression around 11:1..I have a carb & a fogger & currently am spraying 200 shot with the ngk br7ef's I think I should go to a colder plug but am not too familiar with ls1 stuff any help would be great

 

Just for reference, I run a 250 shot with stock compression and use br8efs. Going to a number 9 for the 300 shot.

Personally if I were you I would be on at least #8s.

 

thanks for the input I'll definitely go pick up a set