Need help from you higher elevation guys. When running at high elevation/DA, are you getting more from a larger cfm carb or smaller compared to the same setup at Sea Level? I have the option of starting with a 1050 or 1150 Dominator. 500" combo being built for Bonneville 2019, 4.5" bore x 3.90 stroke, B1MC heads with 2.4" Ti intakes, heads flow well. Not sure of cam specs yet, but an endurance setup. Hoping to make close to 1000hp NA. Thoughts on the carb?

You really need to know the BSFC of the engine before you can get very far. If you know the BSFC and the air density then you'll know how air the engine will use. You'll have to get the engine on the dyno and measure the fuel flow to figure out the BSFC. I'll attach an Excel spreadsheet that will show you what the variables are. I think you'll need a bigger carb than what you have. Minimum would be a 1250 and I think you'll actually want something closer to 1400 cfm if you're going to use a single 4bbl.

I use to race at LACR in Palmdale,SO CA , where the density altitude could vary from 4400 Ft in the mornings at 10.00 AM to 7700 Ft in the after noon at 3:00 PM in the summers, not real high though.
We would have to lean the motors down from spring to summer several jets sizes The track altitude was around 2500 Ft. above sea level. All the Mopar BB I raced and helped tune their like more CFM on the intake side such as going from a 750 CFM carb to a single 1050 Dominator to a six pack and then upwards to a tunnel ram with two 750 or bigger carbs
All of them like more air and fuel like Andy is saying
That was with stock type iron heads, one of my dyno mule motors, 526 C.I. 440 block with a set of CNC ported Indy 440-1 really like the tunnel ram with two Holley 1050 CFM Dominator carbs. compared to a Indy 440-3 single intake and 1050 CFM Dominator carb.

Thanks guys

I have 4150's and Dommy's on cars and trucks that race above 7000 ft. and in my mind as long as carb x is enuff at close to sea level, then keep the carb cfm the same since velocity and vacuum is your friend and the fuel needs will be consistent with the smaller carb in the crappy air for starters. Throttle response will be better and the vehicle should come up on power cleaner across the board. Then there's the cnc'd Dommy's BLP has been machining that I've been selling like crazy which use a HP-1050 body and cnc the venturi's to match their Billet models but open and center the venturi's to 1.720 and add a skirted banjo to increase velocity. I have these on a 5.01 et W-7 dragster, a 4.78 et BB Chevy dragster and many in between who all are blown away by everything I mentioned above...............I guess you can give US some real world results with your testing............

Thanks

For high MPH in the Salt Lake City area, I would use a 1250 dominator. That's what I use on the 1/4 mile here. It slows down the ET a bit, but MPH is 180 vs 177. I can help you when you get here. Just give me some notice.