We have gone 10.009@132mph on drag radials with a production 4.1. The car would have gone into the 9's with ease but the motor was breaking up around 5200 rpm. It could have been a coil/module or even spark plug gap issues but we never got to make a clean pass after that because we broke the #2 stock main cap even though it had a Girdle on. This motor had over 100 quarter mile passes. 95% of them were in the 10's and the fastest being 10.009@ 132mph with 110 race gas along with an old school Fast system. It also made 604 RWHP at around 30 psi boost with a GT42/76 Turbo. The same motor in another car went 10.20's @132 on E85 with the MafPro setup. The car never hooked right though. I also believe the motor made 585 to rear wheels.
The combo on this motor was; 291 cast production 4.1 block, RJC girdle, J&E pistons, BMS rods,( I think stock rods should have been ok) stock crank, Ported Iron heads with 1.77's and 1.50 valves, Flat tappet cam I want to say it's an odd grind like 222/216 or something but not sure. 120lbs injectors, 70mm TB and plenum, Ported intake Poston headers with HKS 46mm waste gate on the cross over pipe, 4" down pipe, TH400 trans with a brake and some crappy convertor, Weldon pump and so on.
I think the #2 main cap broke while trying to spool up the 42/76 turbo off the foot brake when the trans brake switch failed. My buddy stood on the foot brake for a while. When I took the motor to the machine shop they said #2 two main broke, the crank was no good and the Girdle had warped. Since then I got a stock stroke (3.40) Steel crank another stock main cap ( I know I should have gone with billet cap) I also sent the Girdle back to Jason and RJC and had it resurfaced. This motor is going back in my TTA along with a 215-220 Full Throttle speed roller cam, Fully ported TTA heads and a GTQ 71 turbo and so on. I am hoping to make the same amount of power.
All and all, if I didn't think it was reliable, I would have taken all of the guts and stuffed it in one of stage blocks I have sitting around. Who knows, I may crack the block on my first pass lol.
HTH
Prasad