Welcome to CHR, a great place to learn a lot from the practical experience of many others that is not in many, if any, books. I guess I have been in the lower economic class most of my life and it shaped my values but I have been shocked by prices after 50 years. I had a '31 Fordor as a teenager and then a '47 Ford convert at 17 but always wanted a A/B roadster. Now you can buy an entire metal replica '32 roadster from Brookville for about $10,500 or a replica A roadster in steel for about $6400 plus about $1800 for fenders. If you are in that price range you should get a Brookville (Ohio) catalog. I just got the Brookville A-frame and plan to get a 'glass A roadster body , probably from Bebops with fenders for about $4500. You can build a mild sbc 350 for about $1500 or buy a short-rod (400 rods) 383 for about $1800 and then a 700R4 for about another $1400. If you go the route of a '39 three speed that may be up to $500 while a junk '40 rear with a closed drive line can probably be found for around $200 in an unknown condition. However if you are thinking of Zephr gears you get into big buck territory for maybe another $400 just for parts. Then a real quick-change rear center section with gears will be another $1500 or so. You could probably build a running flathead drive line IF (?) you can find a useable block (59AB or 8BA), use a rebuilt standard 3 speed and put new bearings in a used '40 rear and then try to find a brake kit for a front end with a $400 Moredrop front axle. However, that whole drive line is a bit fragile and the parts are so hard to find you will not want to keep or even find duplicate parts AND even after stroking, a flathead will only give 250 H.P. with a lot of work while a rebuilt SBC 350 can easily be built for 270 HP with mild parts. My solution to this situation is to build an A roadster with a SBC driveline and by the way a 8" Ford rear from a mid-'70s Maverick will be just the right width for an A. Consider the hood alone. A steel hood for a '32 can be $1000 while a reproduction A hood is only about $340. Then there is the '32 grill compared to a simpler '29 chromed or painted shell. A recent shock to me was a speedometer with a built-in tach dial for a mere $600! I will try to buy cheaper gauges from J.C. Whitney and build my own fluted wood dash with a Dremel router bit with all the gauges and tach for less than $150. I guess what I am saying is that the only thing that is important to me is acceleration quickness with a 3.55 rear gear and a 700R4 OD for 4th gear mileage and the rest of it will just have to be "functional" plain vanilla with a simple one color in Dupont acrylic. The Model-A roadster has eluded me economically for my whole life with prices just out of reach each time and I am just going to build what I can and only pay high buck attention to the drive line since that is what interests me the most, but just for street use and attending meets. So what if I don't get a "best-in-show", the fun is in the to/from travel for me. Weigh your wallet, but before you commit take a look at a '29 highboy on a full-bracket Brookeville '32 frame as a middle-cost option and after you look and look for a useable flathead block you can pick up a rebuildable 350 SBC a lot cheaper and end up with more power.
I bought three (3) flathead blocks which all turned out to be cracked in one way or another before I got converted to a SBC 350.

Don Shillady
Retired Scientist/teen rodder