Discussion in '1965 - 1973 Classic Mustangs -General/Talk-' started by JT$$$, Feb 9, 2004.
what the difference and how do you tell?
well i believe the hipo is a K code engine (tell by the vin) and it is jsut a more horsepower and torque engine. dont hold me to this but i think thats the basics
If the engine is out of the car, then a good way to tell is by looking at its main caps. HiPo's had 4 bolt mains I believe.
pull the valve covers. if there are screw in rocker studs, the heads could be either hipo heads, or just modified. look at the dampner, it will be about 1/2" thicker than ac or a code 289. if you can pull the oil pan the main caps will be full thickness top to bottom rather than tappering at the top, sorry no 4 bolt main caps on the hipo 289. if the pan is pulled, also look for an add on counterweight right behind the crank gear. if the disst is stock, it will have dual points and no vacuum advance.
Man, then what engine am I thinking of?
RBOHM is correct on all points, one he missed is the slotted (instead of round) holes for the pushrods.
Boss 302 had the 4-bolt mains, the only SBF to ever have them IIRC.
A couple more differences are the HIPO has larger connecting rod bolts, solid lifters, cupped spring perches for the valve springs and screw in oil galley plugs in the rear of the block. The exhaust manifolds are also unique to the HIPO 289.
External differences include:
a. Alternator pulley is larger diameter (high rpm model)
b. Heads have 19, 20, or 21 embossed on leading edge of casting
c. Harmonic is thicker
d. Waterpump is aluminum open impeller type
e. Exhaust manifolds are larger and swept back.
f. Clutch z-bar looks different with curved upper lever.
g. In '65/'66 engine has larger frame bracket forgings.
thanks for the info
are you sure the HIPO heads have the slotted guides for the pushrods??? I thought that the HIPO's used the the round ones.
im pretty sure i have the hipo head and mine are slotted, they are imbossed with a 65 and if im not mistaken either 20 or 21 id have to get the car back first or ask the guy that sold them to me.
ebert, the boss 302 was the only windsor small block that had 4 bolt mains. the 351c also had 4 bolt main blocks, along with 2 bolt main blocks.
the slotted pushrod holes were used on the early (early 64 and below) 289