Mild 454 .030 over. 088 heads. Good pistons rods etc. have found some good deals on all 3 of these blower kits. The 420's with chillers. Which would be the better setup? I trust the people who have them and have a good idea which one I'm going wit just curious for others input

Any one of them would work just fine. Innercooler is added safety but I have read the superchiller type cooler corrodes in saltwater. Stock merc stuff was hard anodized blower/intake. I think TBS is hard anodized as well. I have a 871 littlefield and whipple cooler. The 420 and 671 are about the same size the 871 is a little larger.

Anyone else?

As far as I know the 420 is in between the 6-71 and 8-71 but more efficient than the 8-71. Just what I have been told.

the 420 is like a 7 71,if there was one,but i dont believe it is as efficient as a good 8 71,a 420 with an innercooler is a good way to go,and are out their fairly priced.mild thunder has 420,s on 468 motor,s and made 800 hp with no innercooler.