![hipo mustang hipo mustang](http://classicvehicleslist.com/pics/bigpics/1967-ford-mustang-gt-hipo-289-4-speed-manual-3.jpg)
The intake was fed by an Autolite 4100 carburetor (though with larger 1.12 venturis). Instead, the HiPo relied on the same plain Jane (and heavy) cast-iron four-barrel intake manifold. That was reserved only for the Shelby versions. Not surprisingly, our 50-year-old heads had previously been serviced (likely several times) and featured combustion chambers right on the minimum service limit (52cc).Ĭontrary to popular belief, the HiPo 289 did not feature an aluminum intake manifold. Head work was minimal for our 289, and included surfacing and a fresh valve job (using the factory 1.78/1.45 valve sizes). Since HiPo heads flowed no better than any of the others, we simply converted a set of 1966 C60Z castings that already featured the slotted pushrod holes. Though the HiPo heads are much sought after, nearly any of the more common pre-’66 heads can be converted to HiPo use by drilling and tapping for screw-in studs and upgrading the valve spring package (there is no need to cut spring cups). The slotted pushrod guide holes eliminated the need for either guide plates or (guided) rail rockers. The changes included screw-in rocker studs (no guide plates), cast-in valve spring bosses, and slotted pushrod guide holes (a featured shared with nearly all pre-66 heads). Original HiPos received special cylinder heads (with 52 to 55cc chambers), but the changes made did not necessarily offer any power advantage. 477 lift (with 1.6 ratio rocker) and 310 degrees of advertised duration (roughly 228 degrees measured at. The Elgin (reproduction) HiPo 289 cam featured the factory specs of.
![hipo mustang hipo mustang](http://classicvehicleslist.com/pics/bigpics/65-mustang-hipo-k-code-4-speed-2.jpg)
Completing the short block was a reproduction of the original HiPo 289 cam sourced from the boys over at Elgin.
![hipo mustang hipo mustang](http://classiccardb.com/uploads/postfotos/1965-ford-mustang-k-code-289-hipo-fastback-with-shelby-gt350-updates-webers-1.jpg)
Probe Racing supplied a set of forged, flat-top pistons that replicated the four valve reliefs employed on the 1965 HiPo 289 motors. Also present were a set of 5.155-inch factory rods with ARP rod bolts (longer than the 5.09 rods used on a late-model 302). The boys from L&R supplied a late-model 5.0L block, to which we added the requisite 2.87-inch 289 crank (shorter than the 3.0-inch used in the 302). The solid flat-tappet cam profile offered plenty of performance in the little 289. We sourced our reproduction HiPo cam from the boys over at Elgin.