If you really don't want to tear into it and have a place to store the 273, then start calling salvage yards until you find one with a running, low mileage 5.2 magnum. Swap out the efi intake for a standard manifold, carb it, bolt it up to your 904 and drive the piss out of it for under $800.
Then you can decide later if you really want to continue working on it after daily driving a Gen 3 Challenger.
Don't forget buy a new oil pan cause that 273 pan won't fit a 5.2 Magnum.
I had figured an oil pan and intake woud be needed to put the 5.2 into the Dart and have it function with a minimum of hassle.
Having fallen victom to scope creep on projects and having a car off the road for years and years, I can attest that it sucks wind to look at piles of parts collecting dust while trying to work out "ultimate".
Quote: Where im going with this is the Viper T56 is THE best fitting T56 in an A-body period, and if you keep your eye out can save some money over a Magnum.
This is where you can keep time on your side. Get things running with what you have now. That gives you the luxery of looking for specific pieces at better prices than having a car down and waiting on a specific part or having to pay a premium to get it right now .
