Does any body run the phase 6 bowtie heads i was looking at a pair but i dont really know anything about them are they some good prefromance heads?

They were one of the progression series of bowtie racing heads. Based on the photos I've seen in Vizard's books, they appear to have the same port layout, and the same chamber shape, as 92-96 aluminum LT1 Y/F car heads, 94-96 iron LT1 Bcar heads, and 1996-1999 Vortec iron L31 truck heads.

IOW they are high flow, fast burn heads that were the racing head development that led to the LT1/L31 production car/truck heads. They are good performance heads, but the only advantage they might have over L31 Vortecs is that they might have thicker walls so they might be able to be ported better than the car/truck heads.

Basically If you want to make some horsepower? they will do exactly that! be prepared for high compression ratio`s(11,12-1) if you are using flat top pistons and if you deck the block? the chambers are typically 59cc, special Guide plates available ONLY from GM must be used as the valves are farther apart than standard heads. Dale Earnhart was working with GM performance in developing these heads in the late 80`s and set the platform for future fast burn heads. allot of effort in reducing the chances of detonation was engineered into them and personally I felt they succeeded because I had these in my GTA w/350 TPI and a super ram and Tune-able DFI with 12-1 compression and drove this daily on Regular pump gas! NO Detonation issues for 4 yrs. just a little FYI! some aftermarket headers will NOT fit the 3rd gen with these heads, such as the SLP 1-3/4 , I ended up custom making my own before I found the headmans, I think they will work. The GM performance parts book published in the late 80`s had a page on these heads. hope this helps?