I recently put in a new piston and ring set in my 250 Trailblazer. I had to have the cylindar rebored .020" over. Should I need to reject after this? How can I tell if and how much? Thanks.

 

When I rebored my 94 250 Trailblazer I went .010 over and didnt have to rejet. But you probley could go up 1 size in jet and be ok. Just check your plug to see it is running lean. Also at wide open throttle back off the throttle to 3/4 and see if it picks up speed or stays the same. A jet will run around $5 to $10 depends where you buy it.

 

ViseGrip, you shouldn't have to re-jet but it's always best to double check you plug and see.

 

Thanks. Can anyone remind me again what "normal" running plug looks like vs. a lean running plug. Thanks again.

 

If your running lean the plug will be white, Normal should be a light brown color.