No we didnt strap it down this time. We are gonna do that when i get back from vacation. We just put in the 02 plug and did some street tuning. And, hell yes I can tell a difference..

 

when i had a whipple on a 6.0 7psi was sometimes the knock point. i dont know about an 8.1 but for a 6.0 you might not be able to tune out the knock.

another vote for meth. it will add a fair amount of fuel. you will be able to tune out some of the fuel from the injectors. 20% lower duty cycle wouldn't be hard to see. then add even a little more boost and woohoo

68psi for fuel presure isn't uncomon on the ls1 motors when running boost. it might be a couple psi higher than most see but no big deal. i see around 75psi often. i assume the 8.1 has the same fuel system.