yep, but as I said 1 major thing is different between that combo and mine, compression. That 511 combo that ran 9.70's in a 3500# road runner also had close to 13:1 compression from what I was told. The calculators show not much gain horsepower wise in 1-1.5 point increase in compression. MALEX told me it took compression to run the numbers in his 511 combo with these heads. Not many have experience with these heads. I called Best Machine today and spoke with Chuck about it. He has no experience with these heads either, but his advise was to try more timing and maybe less jet. Some of his combos are running 38-40* of timing and some have 16:1 compression, yeah, crazy i know. Also suggested a different carb like a 4150 1050 for this combo. Chuck also said shaving these heads wont be inexpensive either. Looking at over $500 plus gaskets. He computes my combo to 570hp. That's pathetic in my opinion. I still think it needs more compression, but thats not a very economical way to go. Loosening the vert is $125 . gonna give it some more thought before I pull any thing apart. Thanks guys.