Woa! 60 PSI? I`m pretty sure thats way too damn high. You can damage your injectors by that really qwuick.

 

How do I check the PSI to verify the numbers?

 

Wow! 60 is pretty high. I only run about 42 on my 383.

 

another thought could be your tires. Do you have a smaller diameter rim and tire? being that the stock tires are supposed to be 50 series tire, and say your running a 45 of 40 on your 16in. rim, that would make a big differance. if not, then check your tire pressure. did you put air back in the tire after you went to the track? an under inflated tire also makes mpg go down. just a thought.

 

I don't even get 60 PSI on my blown car. That's way too high. Stock is right around 42-44 with the vacuum line disconnected. 38-39 with the line connected at idle. To check your pressure, you need a fuel pressure gauge capable of reading up to 100 PSI with a fitting for a GM shrader valve.

BTW, what kind of upgraded injectors did you put in and did you have the computer retuned for them?

 

All this was done by the previous owner so I have no idea.