I need help understanding the difference between a 289 and 289 hipo

 

hi perf heads have a raised area around the valve seat area as well as they will have screw in studs .. there may be more .. for some reason my picture didn`t come thru .. google up hi performance 289 heads and you can see some

 

Surely the extra horsepower doesn't come from screw in studs and springpockets. There has got to be more

 

i think the valves and ports are the same .. the valve pockets and screw in studs promote higher rpm`s from the solid cammed motor

 

If you run the same cam, carb, intake, etc., shouldn't the non hipo heads perform the same

 

that is true .. hi po 289`s had steel cranks .. stronger rods with 3/8 ths rod bolts .. a much thicker harmonic balancer .. revved a bit higher due to a solid lift cam so the heads had to be a bit beafier .. not nescessarily better breathing..

 

I have a set of freshly rebuilt 289 HiPo heads. They have been ported & port matched. Also they have larger Chevrolet valves installed. Needless to say the motor runs pretty healthy! Google "289 HiPo" and you can get a lot of info. I have a documented full roller HiPo motor. She runs about 400hp!!!!