408 Engine Question

[Thor]

I held off from posting on this when it first came up and I have tried to hold off again these last few days, but my petrol head has overcome my sensible head, so here goes :
While a Bristol of the period should have a polysphere 318 engine (original 'A'), and it really is a fine engine, if a little heavy, a 340 six-pack is among the best single cam carburettor V8 engines ever, and there is no shame in running one of these in any vehicle which will take it.
I would like to increase my car collection to include a Dodge Challenger of the period, carefully set up to handle (and ride) well on road, powered by a 340 six-pack. You can have a Hemi or a 440 Max-wedge, but the 340 gives all the power you need if you're not actually drag-racing, and is usefully lighter in the nose of the car.
Anyway, as others have said, the 340 will not be difficult to sell.
As to the originality question, I think these V8 Bristols are amazingly good cars to drive, even in modern traffic. I feel quite strongly that using more modern Mopar V8s and more up-to-date Mopar transmissions are very positive things to do, so that the beauty of the cars and the good qualities of the chassis can be used more frequently, if not daily, with the better economy, driveability, and emissions of the more modern drivetrain.
So you might consider rebuilding your 408 with a Magnum 360 with a 4 or 5-speed and lock-up transmission, its not that difficult !