6.20'S with stock 074 heads . Had a miss down track..never got a clean pass with it. Ended up it had a broken valve spring. I only made 4 passes with that motor..so I haven't messed with jets or timing or any of that yet. Just bolted it together and ran it.
Bought a set of Brodix 2x over the winter. It probably won't run it, and it aint no big deal if it don't, but I would love to get in the 5.90's.