I've been to the dynos quite a bit lately. I've been trying to get the performance aspect of the car squared away so I can work on other things, and it's proving quite difficult.
At any rate, the M50 equiped 325's came with 190hp stock at the crank. About 15% is attributed to parasitic loss on manual drive cars, and about 17% on automatics. So, you figure 161hp or so brand new. I've seen them range anywhere from 158-160 on a Mustang Dyno.
Oh, and incase you were curious, the following is a dyno run with my stock chip and fuel pressure regulator.
Since then, I've added a custom built chip from AA. The chip fixed the low rev hp/tq (I actually gained 17hp/18tq@3250rpm), but I lost peak power and torque. Waiting for a new chipset. Getting expensive.