Do you guys think it would be safe to run my truck with a 4# pulley with a chip that is burned for the 6# pulley? Could this cause any damage? Any thoughts on this would be great, thanks.
Rich

 

you should be ok

I would think you would just be a little rich.

 

I believe the correct term is pig rich. and yes you will be ok

 

Whats the biggest pulley you can run with no chip?

 

It would be safe but you would probably be a little rich. Why not just send your ship back for a reburn. They should be free!

 

depends on the truck. a dyno run with a/f readings will give you an accurate number. Usually 2-3lbs over stock will be as high as you can go.

 

Hey Rich, this is Rich, and your truck will be rich with tune for 6lber and using a 4lber, BUT... Yes it will be safe!

 

Thanks for the info. I have 2 chips that are burned for the 6# pulley and I'm going to send 1 back to get reburned by Sal and get it upgraded for the NX kit I bought.

 

Mine is burned for 6 lbs and I run only 4 in the winter months.
My truck is running great this way and has for some thousands of miles already since I took my Upper off in Oct. There really isn't that much differance between the two tunes. A matter of fact with the weather being in the 20's in NY and even colder for many weeks already this winter, the tune works perfect since the motor automatically adds timing and should be offset with a safer tune anyway, I'd leave it if I was you. I'm running Denso IT-22's which is 2 ranges colder than stock, and I have absolutely no richness problems at all, A matter of fact I ran a 12.8 this way just to test and see how I'd run without my Upper Pulley and a super rich tune.