But dont sweat it.the C code that you have is a good solid motor that will handle a lot. Hipo's are fairly rare so I would bet against one showing up in your car if it wasn't originally equiped with one. If I had to guess I'd say that whoever you bought this from slapped a 4 barrel on it with a Hipo dress up kit and passed it off as a Hipo motor. And finally a Hipo will come with a solid lifter Cam if it's got a hydralic bumpstick it ain't a Hipo. Most noticable would be the cast in valve spring pockets, regular heads don't have them there are a few other differences also but it is actually the same basic head that comes on the C code and you won't see a performance gain by using them. The Heads are also a different casting but you won't notice the differance unless you pull a valve cover. More noticable is a heavier wider harmonic balancer.
The Hipo will also have a small extra counterweight that goes on the crank. A Hipo will also have a brinell tested crankshaft and will have a letter K stamped after the regular casting number, easy to fake, and again the "regular" crankshafts will do just fine anyway.
#289 HIPO CRATE ENGINE UPGRADE#
The block itself is vitually identical except that it has heavier main bearing caps as this is covered most wouldn't bother to upgrade a plain 289 block and you really don't need to it will handle the HP increase well enough and putting the heavier mains on a regular block requires machining which can be expensive. Click to expand.You can't just increase the HP and have a Hipo motor the are a few things needed to "clone" a Hipo.