Hi,
I'm sorry I had not noticed your post sooner.
We had a gentleman tell us he saw an increase of 10hp at the dyno. Another gentleman saw an increase of 5mph at an 1/8th mile track, on a 2004 F350 dually 4x2. In 2007, I think it was 2007, at the Bash on the Bayou, Shaun dynoed 442hp, on the fuel system and looney tune only. I think it was 442, if not, somewhere around there. There's a thread on compdiesel about it. It's just that I'm getting older and my memory is beginning to fail me.
Thanks,
Vivian