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
![shruggy shruggy](/ubbthreads/images/graemlins/custom/shruggy.gif)
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
![up up](/ubbthreads/images/graemlins/custom/thumbs_up.gif)
That was with stock type iron heads, one of my dyno mule motors, 526 C.I. 440 block
![blush blush](/ubbthreads/images/graemlins/custom/blush.gif)
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.