I think some of the FAST guys use the extrude honing process to kind of hog out and polish the manifolds. It's expensive, but supposedly it works pretty well. Might be worth a look if you really want to use your manifolds.
All of the F.A.S.T. guys are stokers with mega roller cams. The Hemis have two of the cylinders switched in firing order to smooth out the idle (the car must have a "stock" sounding idle). Their tricks are not limited to anything internally in the engine. The manifolds are not the key to their speeds, but just a component. Their suspensions are tricked out, the fuel systems are tweaked, they run the lightest combinations possible. It goes on and on. Plus they run on bias ply tires. The fastest right now is a 10.30 from a L-88 Corvette with Dudek's Hemi RR running in the 10.40's at 135mph+. They have tried Extrude Hone, but had better results just from porting the manifolds on the Mopars.
As for my Pure Stock GTS, the best time is a 13.26 @ 103.46 on 205R70-14's on 14x5.5" rims. 3.91 gear, 727 trans. 3600lbs with me in it. No head work, no manifold porting. Factory intake and AVS carb, and factory exhaust manifolds. :)
