I find it interesting how far we have gotten from the original intent of this post. It's a question about heads. And it had turned into a bunch of guys saying that I'm slow..... like I said before a couple times. It's been down the 1/4 in one event. Of course it needs to be dialed in and I can hopefully find more speed in other areas too. Are you guys getting those numbers et/mph from internet calculators or having a similar setup with Timeslips showing these mid 12s or 11s as newbomb said without spray? That seems awfully fast for a car that might make 350 at the crank maybe less. If I can get my 60' down a couple 10ths I'll be in the 12s for sure. And it's something I'm gonna work on regardless. But I'm asking about aluminum heads. I plan on messing with the carb this season aswell but my WOT afr seems pretty good at around 12.6 and is similar while spraying. I run the light spring in my secondary. Could change the cam to a bit higher rpm but it's a street car mostly. By tune the carb you mean lean it out some more? Seems like it's in a decent range. I have an afr gauge in the dash. It idles a bit rich but WOT doesn't seem to bad