There's a post buddy made on here awhile back about how to set the timing on one. Might be able to talk to him and find a LP wide band (not sure if they're different than a normal gas one). Then get it pretty close from there?
I need to hook a laptop up to my 6.0 to tune it and I gotta buddy that's a forklift mechanic and he'll bring his "fart sniffer". He made some adjustments to the mixer on my 350 to get the A/F correct.