[RUQWKNF]

Ok, here's the skinny.
The way that PTE names all of their turbos does indeed have a code to the madness.

In the part number, when you see the letter R that means Roller or Dual Ball Bearing. This is for every turbo that they sell that has the R letter in the part number.

The E means TO4E compressor cover, or in Precisions' case, a casting that they have made that is similar to a Garrett TO4E but slightly better. It has a .60 A/R and 3" inlet and 2" discharge.

The S means TO4S Garrett casted compressor cover. It has a .70 A/R and 4" inlet and 2.5" discharge. This cover comes from Garrett and is machined for a 60-1 compressor wheel when PTE gets it. They then machine it out to fit whatever wheel they want it too fit, all the way up to a 70mm comp wheel. It is also available with a Ported Shroud option which makes the part number a SP.

The H means it is a Precision casted race series compressor cover with a 4" inlet and 3" discharge. The new style H cover has the Precision logo casted into the side of the discharges' volute. It has a .75 A/R and 4" inlet and 3" discharge. It is also available with a Ported Shroud option which makes the part number a HPS. You can also get the H cover with a large pressed on 6" inlet bell, which will not work on the Turbo Buick. Doing so would give you the HB designation in the part number.

So in the above turbo listings, if you wan the 67 compressor wheel and P-trim turbine wheel in dual ball bearing with the standard H compressor cover and .63 A/R turbine housing, you would need to order this part number.

600-1551 6776RH Ball Brg with a THB3-76 .63 A/R turbine housing.


With regards to the other funky letters, (HPQE) they could be one of two things. Either 1, they are coming out with some new versions of this turbo and have given them a new part number. (aka Boosted series) Or 2, someone has gotten the lettering codes all screwed up and it's either a typo or another vendor is giving it their own part numbering system. But official PTE part number code letters are as follows, Compressor covers E, S, SP, H, HPS, and HB. Turbine housings are a whole other story.
When Rod and I were working on the price sheet and part numbers way back in the day (2003), I had mentioned that we needed to put a better explanation of the lettering codes with regards to the description, but it went in one ear and out the other. I was constantly struggling with this very same issue with customers all the time. At least 3-5 calls a week. "What the heck does HPS mean? What does R mean? What is an HB cover?" The other mistake that they made, and still make to this day, is total lack of pictures to go with the descriptions. If he would have taken the time to go around and take pictures of each compressor cover, just the compressor cover alone and make a page that was dedicated to just comp covers, it would have eliminated pretty much all of these confusing questions.
Ah well, I'm just glad I don't have to deal with all that frustration now. Life goes on....
I'm going to make this one a sticky for future reference as this topic comes up a lot.
Hope some of this helps.

Patrick