I have my pyrometer installed post turbo. If you add 300 deg, you should be safely in the ballpark.
They say if it's in the manifold, it's more accurate. Probibally is.
I'd skip the 215's and go for the 370's. Theyre actually cheaper!! Just my . 02.
If you have an older truck, you might need/want the delivery valves. I think Piers has them on sale this month.
Eric