well sir I have had 4 big block darts and dusters with no issues.and 2of them were 60 over 12 to 1 motors.and usually run a 2 inch. spaser with that 7 blade stainless fan.if your having cooling trouble with a big block something else is wrong...I hate to see you go throw all that expense if you don't need to..if its to close do you have the trans setting in the stock trans mount if so you should have about 4 to 6 inch in front of your water pump If memory serves me right..that and a 180deg.stat.you should be race ready..just trying to help not trying to start an argument......hell if you can put a hemi in them with no issue why can't you do a bigblock...hope this helps Artie