Mopor V8 in '48 Plymouth

I've just about decided to abandon the original flat 6 and force a V8 into my '48 Plymouth Coupe. Got an '85 Chrysler 5th Avenue for a donor. Good running 318 with a 904 auto behind it. I'd also like to to use the rear end if possible. I haven't done the messuring yet (hopefully this weekend) but hope it will be wide enough. I'm wondering if anyone out there has done this or a similar swap. Any advice or warnings you might have could be helpful. I expect surprises along the way (never had a swap go really smoothly) but wouldn't mind avoiding some of the pitfalls.

I plan to keep the old flathead 6 as a future upgrade for my '38 sedan.

Good for you, keep a mopar in a mopar I think Ply-Do makes a kit for this. Check street rodder for their address. A buddy of mine has one in his 37 Ply. I am running a 340 from a 72 cuda in my 37 terraplane along with a 727 trans. and a 8-3/4 rear. Good luck I think you will like that drive train.