mm&ff head test - intake too small?

Discussion in 'Fox 5.0 Mustang Tech' started by MUSTHAVE302, Dec 8, 2003.

  1. I recently picked up the MM&FF that tests several aftermarket heads such as Ebrock vic jr., Trick Flow R, AFR 205, Brodix M2's, etc. Initially, they ran the heads on a 408 w/ solid cam (around [email protected] i think) and super victor intake. They had piston to valve clearance issues, and for some reason decided that they should be testing the heads on a slightly milder combo - i think b/c the 408 was too radical for most street apps. Anyway - they went to a 393 w/ a hydraulic roller (i think around [email protected])and vic jr. intake. Seemed like the 393 combo was about 75hp or so off from the same heads on the 408. I thought this was a lot from the marginal change in cubic inches, so most of it came from the cam & intake. Also - the HP really leveled off on the 393 for almost 1000 rpm. HP charts weren't provided on the 408. As the heads produced a lot more power on the 408, they didn't seem to be the limiting factor. While the 393 cam was smaller - it wasn't drastically so - it certainly should have enough duration for making peak power in the 6000 rpm range. Most heads peaked around 6500 w/ the 393. So - to my feeble mind - that leaves the intake manifold or the carburetor. Did anyone else read this article? What are your thoughts? My friend is slowly gathering the pieces for a 393 - and I'm thinking he should lean towards the super victor intake. Any thoughts and experiences are welcome.