Tech?? Easiest engine/trans in a 53 Mercury

I just bought a 53 Mercury with no engine or trans- I'll post pics shortly. What is the easiest engine to put in this thing? SBC, SBF? I would rather put a Ford in a Ford if possile. I am assuming at this point that 49-54 Ford and Merc are about the same. By easiest, I mean the least amount of cutting/re-engineering.

What about the trans? Although not trad, I would love an overdrive transmission like a T-5 or an AOD so I can go fast without 6000 rpm on the interstate . Would these transmissions put the shifter in the middle of the seat?

Thanks for the advice

 

[I was gonna say 390 plus ford-C6-to keep it ford powered- but since you want overdrive -I'd say late model 302 Ford.you can swap its injection for a carb and intake and an older distributor] [or a small block chevy] would be my choice].....

 

Doesn't get much easier than this:

 

Easiest would be a good ol' 53 Merc flathead with a stock 3 speed overdrive.....not being a smartass here. Ain't nothin wrong with that 255 merc and O.D. With a little tweaking, you can get 140 hp from it and it'll still be streetable. With the o.d., it'll get over 20 MPG and cruise on the interstate at 70 all day long.
I'd certainly change the electrics over to 12 volts and use an o.d. solenoid from a 56-63 ford overdrive tranny.

 

Rocky,- Right on! I was just composing a reply, but with my slugish brain you beat me to it. Might be alittle conservative with the HP though.
Ted