Called Dyers

3" is pretty standard. You'll probably be okay with a SB. With my 440 there's no clearance for any fans. Dropped PS to eliminate an accessory pulley too. Keeping any of it would have required moving the radiator into or in front of the core support. Instead I run a SPAL pusher.

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Hi, what spark plug brand and range do you run on your big block, I built a 451,440 source heads,671 blower,, thank you