I dont have the Layback motor in mine its the older 98 Zr 600 small block with the 720 D&D kit, I just picked up a Layback 720 thats on its way and going to try make that fit also, the M1000 you need tons of fab work and I believe that guy also turbo'ed that sled. With the motor layed back that much in that chassis would be insane for handling. I will be posting pics soon with the motor in all finished up. But those older 720s have crazy power for such a tiny motor.
Sounds good man, I think i want to try the 1000 regardless of fab work but your small engine sounds light and easy to fab into the IQR. Good luck, make it happen!