which sparkplugs should i use for a stock 5.3? I have some spare tr-6's but there are prolly too cold for a stock motor.

 

I think most opt for the NGK TR-55s on the stock motor. TR-6s for nitrous or FI.

 

Bosch " Platinum-Plus-4 " guarantee performance increases or they'll buy them back.
Four ground electrodes and no gap to set. I've used them in a 4 banger and it seemed to zip a little better. My truck only has 7k and is still on the stock ones.
Electricity always takes the easiest path to ground so I don't know if it hits more than one ground electrode at a time. It seems like it would always be indexed right,though.

 

what is the gap i need on the 55's? isnt is .65?

 

TR-6 is a stock type plug in the gap they come in.

 

the tr6's are gapped at .35

 

TR-5 ... my mistake. Yea, NGK, the bigger the number, the colder the plug.

TR-5 would be 'like stock'.