I have a Comp XE268 (268/280, 477/480, 224/230 at .050, 110 LSA)in my 400. 73 RR. I have the 175k MP converter behind it. Flashes to about 2800. You could use a stock converter with it but i wouldnt recommend it. Its a little soft on the bottom. Has a little bit of a lope and pulls pretty good to 5800.