All the 63-64 B-Body Dodges are on a 119" wheel base except the station wagons that were left on the 116" wheel base of the 62 Dodge models. The 62-64 Savoy/Belvedere/Fury/Sport Fury’s and the 65 Belvedere/Satellite passenger versions remained at 116" thru this whole period. With that said, a replica of a super stock 330 or 440 2 dr post sedan could be made from a 330 or 440 4 door sedan or even a Polara 4 door hardtop it you had enough cash and bodywork skills. It does seem kind of cost prohibitive when you weigh out the fab costs, donor doors and quarters for what you have vs just finding a decent 2 door post sedan shell and going from there. IMHO,use the 4 door as you stated for a parts car. Most of these 62-65 B-Body cars have known and expected rust problem areas like the inner cowl and firewall areas, floor pans, trunk floor extensions and such, and a solid 4 door car would be good to have "just in case"

Here is a little more info regarding the factory SS cars relating to wheelbases.

Actually all the Y9-09 lightweight Max Wedge and Hemi cars from 1964 and the 1965 WO51 and RO51 "A-990 Package" cars were altered wheel base cars compared to their production counterparts. The 62-and 63 B Body's used a rear leaf spring that was 55" long with the front bolt eye 20" forward from the spring pack center bolt. 1964-65 production cars used 56" long springs with the front spring eye 21" forward of the axle locator pin/spring pack bolt. The 64 Stage III Maxies and the 64-65 Hemis utilized a Super stock spring that was also 56" long but had the front mounting eye 20" ahead of the spring pack center-bolt/locating pin. The difference was subtle but effective. In 65 the Dodge 330, gave way to the Coronet and a subsequent 2" reduction in wheelbase, but still 1" longer than the Belvedere's 116" at 117". This was accomplished by the Dodge having a 1" longer front box sectioned spring hanger bolted to the unibody to mount the front of the rear leaf spring. So by putting the Belvedere front spring hanger part #2403742 which is 2 1/4" from the front mounting face to the spring eye bolt hole on the Coronet, and using the 8 leave right and 6 leave left Super stock springs on them, all the A-990 cars had 115" wheelbases. 1" shorter on the Plymouths and 2" shorter on the Dodges compared to the 1965 regular consumer B-Body’s.

Ed.