Discuss 351 Cleveland head choice question. on AllFordMustangs.com, the place for Mustang enthusiasts.
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For those of you who know these engines, what head choice would you make. I already own sets of the 4bbl open and the Aussie heads. Are the open heads any good? Thanks in advance
all depends on what you want to do. for street power the aussie heads are pretty decent with the small chamber and the medium sized ports
the 4 barrel heads will make great power at high RPM because the massive ports flow tons of air, but at low RPM the massive ports hinder the velocity so they're not as great off the line.
the 2 barrel heads are pretty bland compared to the other two because of the large chambers you need pop up pistons to get much above 9:1 compression, unless you're going forced induction. then they're decent.
Thanks for the feed back Pockets. The engine is going to be a hot street set up, as far as performance goes. My experiences with the 400 in my Ranchero are that the open chambers tend to want to spark knock, run on, deisel whatever you want to call it upon shutting the engine off. Do the open 4bbl heads do the same?
I"m running 10.5 to 1 compression. I didn't look at the diamond pistons for this build I handed it off to a builder and came back later. In previous motor iterations they all had valve reliefs cut into ross pistons them so I would assume the same hold true.
Well that makes me feel better about the run-on that I experience with my 400M in my '72 Ranchero not being connected with the open chambers. I'm starting to source parts for this next engine build. Thanks again for the input.
351 Cleveland head choice question. 
