I had an opportunity to purchase and drop in a new crate and dyno tuned 525 HP 392 Gen III Hemi (Non supercharged.) into my non matching numbers (But period correct) '69 GTX. My decision was as follows.
Spend $16k on engine?
Upgrade K-frame and mounts to install?
Rewire for new ignition.
Reroute fuel delivery for injection.
Change exhaust.
Change bellhousing/adapter.
Change clutch
(This is just to name a few.)
And most importantly? Pull a very decent running 440 all to gain (approx) 90 HP?