325 at the crank I'm guessing. Of your not wanting to run a stall the 212/218 mentioned earlier would do good. I ran that in my 5.3 for a while without a stall and had very good drivability.some good 1 7/8 headers 3 inch exhaust with y or h pipe. Now the most bang for your buck is going to spray! The stock bottom end should take 125 pretty easy if tuned correctly.