Stock motor 2871 how much boost?

[Oneoverwrx]

Hey guys i have been searching around a little this morning for the limits onb a stock redtop. I have found people making 350-375 with no issues but I have yet to find someone who says i have made xxx at xx psi on a stock motor.

Reason for me asking is because i am tuning a buddies car with a 2871 with a .86 housing. Car has all the supporting mods/ bolt ons. Car has a little headwork but is still on stock cams. We are tuning with an safc. He is on sti injectors and a walbro pump. He has a nismo fpr but it is not on the car yet. The car is not a daily driver and we literally have race gas at the pump less than a mile from his house. My question is what is the safe boost limit for this car? Also can you max the stock motor out with pump gas boost(like 20psi) or would he benefit from 23-24psi and some 110oct. I am sure we would be at the limit of the efficiency of the turbo at that point but would the motor take it. Should i tune it on 93 to something like 15psi and then maybe tune a mix of pump and race to something like 20psi to be safe of what?? He is wanting 350+ and isnt wanting to build a motor until after this summer. Any help would be great.

Thanks
Phillip