I am currently in the middle of my TBI motor rebuild as a result of too much laughing gas (oops). Anyway, I want to properly fuel it this time around. I'm running stock 062 vortec heads, GMPP TBI intake and a mild flat tappet comp cam (.425/.440). 10:1 pistons, stock crank/rods. I had a tune made by TBICHIPS when I first built the motor about 5 years ago. I have 350 tbi injectors at about 15psi. According to TBI fueling spreadsheets, I am way under fueled for my setup. I picked up a set of 80#/hr big block tbi injectors and requested a tune from TBICHIPS for these injectors and my motor and was told they were way to much for what my setup and I was fine with what I have. Any input?

BTW, the car ran great before, running consistent 13.6 1/4 mile times at 100-103 mph.

 

61 #/hr @ 15 psi FP are good for around 248 FWHP
80 #/hr @ 15 psi for around 325 FWHP

Dyno simulator program can give a rough hp estimate.

 

My car traps the same as you and I run the 80# injectors @ 12 PSI. I am basically maxing those injectors out at that pressure and see the duty cycle at 90% in the upper RPM and MAP areas of my VE table. If I were you I'd probably run the 80# injectors and get it tuned using a wide band.