The 4AGE is approximately 278lbs and the C-52 is approximately 70-71lbs... This is a grand total of approximately 348lbs.
I highly doubt you have your car down to 2000lb considering your weight guesstimates at this point and your surely not saving 600lbs in engine swaps. Unless you've taken your car to the point where it's unsafe for the streets, by removing certain glass, bumpers, crash protection devices amongst other things... I'd guesstimate your probably weighing in somewhere in the 2250 region. This considering some minor removal of insulation and maybe the a/c compressor and associated plumbing. I dont know whether you have a fully loaded/stripper model or t-top/sunroof/hardtop, but Im just making a generalistic edumacated guess on the low side weighing in your favor.
Now if you could get down around the 1900-2000 lb weight, loosing all streetability, I would think it might stand a chance of being alright. It would still need to be alot lighter to receive any real benefit.
Again, consider the much heavier weight and what gearbox/axles you select as the weight is still on the high side for any motorcyle application. Consider what the cargo limit is on a 450lb bike... Im not sure, but I would suspect it be no more than 300-400lb of cargo. This gives you a limit of about 750-850 lb. Your looking at moving an object about 3x the weight. Not something I would want to try pushing w/ the engine. The load is an important factor.
Its your money, your car and your time.... Research everything extensively, dont guesstimate.
Just adding my
Good luck to you in your endeavours, I commend your eagerness to try.