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GMC71k20 · 08-24-2021, 01:38 PM

i highly recommend putting vortec heads and 6" rods on the 400, its an easy 500 ft/lb under 1800rpm with a rv cam

google the impersonator 406 magazine build

my thoughts regarding the original 400 blocks depend on your budget, machine shop connections and/or patience for engine swaps. the numerous anecdotes about cracked 400 blocks and heating issues that would could be avoidable if you pay for a dyno-test/warranty crate engine

i have an original block and vortec heads with 6" rods and the speedmaster intake. This makes the sm465, 4.10s and 35" tires very easy to drive.

08-24-2021, 01:38 PM	#18
GMC71k20 Registered User Join Date: Aug 2002 Location: mass Posts: 1,277	Re: 400 sbc in a ‘70 K10 i highly recommend putting vortec heads and 6" rods on the 400, its an easy 500 ft/lb under 1800rpm with a rv cam google the impersonator 406 magazine build my thoughts regarding the original 400 blocks depend on your budget, machine shop connections and/or patience for engine swaps. the numerous anecdotes about cracked 400 blocks and heating issues that would could be avoidable if you pay for a dyno-test/warranty crate engine i have an original block and vortec heads with 6" rods and the speedmaster intake. This makes the sm465, 4.10s and 35" tires very easy to drive.