I did a lot of research about these two turbos. My truck being an auto came with a hy and I had problems with high egts with my mods. Some guys said the swap was worth it others said very little difference. I picked up a hx last week for $150. It bolted right up and made a huge difference when in the throttle. My boost went from 26 to 34 and my egts dropped 200-250 degrees when pulling. I took my new 14k toy hauler out for the first time and never would have made it with the hy. I easily hit +1300 degrees with lighter trailers before. With the hx I pulled most hills around 1100. I'm impressed. Anybody with the hy not wanting to spend a lot on a turbo right now I recommend an hx.

 

For a few more bucks send that hx up to high tech turbo in SLC and make it a hybrid, you will really like that.

 

What do they actually do when they do hybrid?

 

I too experienced excellent results, after installing a "cheap" hx, huge improvement over that hy

 

It's all explained here
http://www.htturbo.com/cu.htm

 

The hybrid HX35/40 replaces the stock 54mm 7 blade compressor wheel or 56mm 8 blade compressor wheel with a 60mm 6 blade compressor wheel. If your HX35 was pre 98.5' it has a 56mm wheel and the larger 60mm wheel can be installed without machining the backing plate. 98.5'-02' Hx35's came with a 54mm compressor wheel and the backing plate has to be machined a little bit to accept the 60mm wheel. Also, 98.5'-02' HX35's have the wastegate actuator mounted to the compressor cover so you have to buy the slightly more expensive cover with the cast-in mounting ears to accept the actuator.