Quote:
Originally Posted by Mr Anonymous
your combo is an almost a perfect copy of the 1968-1969 Oldsmobile 400 as used in A-body applications (4-4-2 and vista). 4.25 stroke crank as well.
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The "long-stroke" 400 engine is HATED by Olds people. It was an obvious cost-cutting measure; Olds only had to machine one stroke on their crank castings instead of having the old 400/425 stroke and the "new" 455 stroke. They didn't rev, but they did blow up.
I would have put the original engine in a plastic bag, tossed in a couple of desiccant pouches, vacuumed the air out of it, and sealed it up. Stash it under a work bench in the garage.
I'd build an engine with more bore, less stroke. More bore
allows bigger valves 'n' ports; but does not require bigger valves and ports. Bigger bore reduces bore shrouding of the valves--heads flow better on a large bore than a small bore.
Torque is a function of displacement and gas velocity through the ports/manifolds, not stroke length. A Buick 455 makes as much or more torque than an Olds or Pontiac 455, but has a much bigger bore and a shorter stroke.
A similar mild-cam 400 short-block, with your original heads would likely be more-tractable and have a wider power-band than the long-stroke 350 short-block with the same heads.