A while back the Hemi conversion setup ran around $5K. Stage V makes some of the nicest heads around. If one could get a really good deal on a set I think it'd be worth it, especially for a street car. Most street cars never make the kind of power they are capable of. It's more important to many people to have the Hemi under the hood than it is to run 9s.

My church has a car show on Father's Day and someone brought in a Hemi GTX. Every single person who walked by the car stopped and looked and oohed and aahed over the engine. That includes people who I know well to not care one whit about horsepower. It wouldn't have mattered if there was a 383 shortblock under those heads, it just looks so cool and unreal.

So if you're looking to build an 800 hp engine then the conversion heads have little value. If, on the other hand, you want to build a Hemi for your street car they might be very worthwhile. It's the hardcore racers who make up the backbone of this particular forum who can't see the worth.

Pistons for Hemis cost money, no matter what diameter they are. That isn't a good reason to pooh-pooh the question.

Years ago on this board was a guy who called himself Hemiman and he ran Hemi heads on a 440 block and turned some respectable times for a street car, and had a blast owning a Hemi that cost about half what a real Hemi would have cost. That was using the stock 440 crank.