Did back to back runs a couple weeks ago. 950 QF down leg 2 passes, QF 4150 1050 annular bolted on with block off and upped the jets. Fastest et to date by .26. First 2 passes went 11.50 and 11.45. Bolted on the 1050 and went 11.19. 4250# street car on pump gas. $700 and .25 makes it the mostest for the leastest for me. Also, their tech and customer service was great.