if he has Banks spank him(he deserves it),he wont stand a chance against the SCT Custim tunes,not a chance..
the ATS E-Power or the PPE are the best off the shelf tuners but with the 5SP Allison you realy cant run more then a 100RWHP extra(total of 400RWHP)before the tranny goes into limp mode but thats only in the top 2 gears now the 1st 3 will easily handle 500+HP without any mods so watchout for the off the line runs..also the 6SP Allison doesn't mind 450HP when tuned with EFILive and let me tell you about EFILive,if tuned properly on a LBZ or LMM mid 12's are very possible on stock turbo,injectors and no bottles.only mods needed is a $2000 tranny upgrade,$500 fuel system(including lift pumps),$400 IFS upgrade,exhaust,guages and $750 on EFILive.thats it,now add a bottle and low low 12's is in the sites.