If you checked the parts book you would see the 1967-73 Imperials used the same floor pans as the Chrysler. The front stubs are different. Also, the differences between the Fury, Polara/Monaco and Chrysler are in the centre to rear floor pan extension - just ahead of the rear seat. The same place the differences between Valiant and Dart, when their wheelbases differed. Also, the Fury and Polara/Monaco models used the same torsion bars, while the Chrysler and Imperial both used unique bars. >From the 1972 parts catalogue : Front floor pan (toe board to rear extension) : 23-32-22 Fury : 3570 436 Polara/Monaco : 3570 436 Chrysler : 3570 436 Imperial : 3570 436 Centre floor pan (rear seat) : 23-32-24 Fury : 3445 441 (wagon - 3440 860) Polara/Monaco : 3445 441 (wagon - 3440 860) Chrysler : 3445 441 (wagon - 3440 860) Imperial : 3445 441 Centre floor extension (between front and centre sections) : 23-32-25 Fury (except wagon) : R - 2902 890 / L - 2481 401 Fury wagon : R - 2902 892 / L - 2481 813 Polara/Monaco : R - 2902 892 / L - 2481 813 Chrysler (except wagon) : R - 2900 846 / L - 2481 403 Chrysler wagon : R - 2902 892 / L - 2481 813 Imperial : R - 2900 846 / L - 2481 403 Rear floor pan (trunk) : 23-32-48 Fury : 2900 783 Polara/Monaco : 2900 783 Chrysler : 2900 783 Imperial : 2900 783 NOTE : All wagons used 2481 824 Now, for the front stub (frame) : 13-01-1 Fury 6 : 3611 353 Fury V8 : 3611 352 Polara 6 : 3611 353 Polara/Monaco : 3611 352 Chrysler : 3611 351 Imperial : 3583 196 Crossmember #1 : 13-11-5 : Fury : 2493 925 Polara/Monaco : 2493 925 Chrysler : 2493 925 Imperial : 2534 056 Crossmember #2 : 13-11-5 : Fury 6 : 2934 938 Fury V8 : 2934 936 Polara 6 : 2934 938 Polara/Monaco : 2934 936 Chrysler : 2934 936 Imperial : 3583 199 Crossmember - Rear anchor : 13-11-5 : Fury : none Polara/Monaco : none Chrysler : none Imperial : 2071 507 (NOTE : rear anchor on all but Imperial is two piece and part of stub frame, and not catalogued as separate pieces. Crossmember Transmision mounting : 13-10-1 Fury : 2925 299 Polara/Monaco : 2925 299 Chrysler : 2925 299 Imperial : 2925 299 I do not know where your information came from for the exhaust manifolds, as the 1972 C body cars use the same exhaust manifolds for all four car lines. The 400 and 440 use the same manifolds across the board. For the exhaust system, Chrysler pipes came in four sections : 1) Exhaust pipe : Manifold to extension: 11-05-1 440 V8 : All - 3466 633 (early) or 3583 980 (late) 2) Extension pipe : Exhaust to muffler: 11-05-4 440 V8 : Fury except wagon : 3583 821 440 V8 : Fury wagon : 3466 252 440 V8 : Polara / Monaco : all : 3466 252 440 V8 : Chrysler except wagon : 3466 638 440 V8 : Chrysler wagon : 3466 252 440 V8 : Imperial : 3583 750 3) Muffler : 11-01-1 440 V8 - All : 3466 644 (Al) or 3466 645 (Zinc) 4) Tail pipe : Muffler to rear bumper : 11-09-3 440 V8 - All - 3466 956 I believe it is very obvious the differences in length from Fury to Chrysler are in the body while the Imperial is in the front stub. Remember, all C body wagons were on the Dodge 122" wheelbase. Thus the Chrysler wagon used the wagon body with the Chrysler stub and still had a 122" wheelbase. As for the interior dimensions, there is not much difference from Chrysler to Imperial. You can also tell that Fury and Polara/Monaco shared rooflines, as did Chrysler and Imperial : Leg room = Front / Rear (4-door hardtop) : Fury : 41.8" / 38.0" Polara / Monaco : 41.8" / 39.1" Chrysler : 41.8" / 41.5" Imperial : 41.9" / 41.2" (FYI : all 2-door harrdtops, except Fury formal hardtop, have rear legroom of 35.2") Head room = Front / Rear (4-door hardtop) : Fury : 38.0" / 37.2" Polara / Monaco : 38.0" / 37.2" Chrysler : 38.1" / 37.0" Imperial : 38.3" / 37.0" Hip room = Front / Rear (4-door hardtop) : Fury : 63.2" / 63.4" Polara / Monaco : 63.2" / 63.4" Chrysler : 63.3" / 63.3" Imperial : 63.1" / 63.1" Seat height (front / rear - 4-door hatrdtop) : Fury : 9.2" / 11.6" Polara / Monaco : 9.2" / 11.5" Chrysler : 9.2" / 11.5" Imperial : 9.0" / 11.5" Again, the Imperial has more legroom than either the Fury or Polara / Monaco, but actually has LESS legroom than the Chrysler. You can see the increments from Fury to Polara / Monaco to Chrysler as the wheelbase increases. But the Imperial has no more legroom than the Chrysler - because the floorpans are the same. The decrease is due to the increased padding on the Imperial seats. The increase in Imperial front headroom (0.2") is undoutedly due to the lower front seat (0.2"). Sorry, but the Imperial's increase in wheelbase over the Chrysler is all in the front stub. From the firewall to the rear end of the main trunk floor, it is all Chrysler. Bill Vancouver, BC ----- Original Message ----- From: W Bell To: mailing-list@xxxxxxxxxxxxxxxx Sent: Wednesday, March 10, 2004 10:17 PM Subject: IML: where's the wheelbase difference? With all due respect, I believe that if you check the vehicle architecture between a Chrysler and Imperial in the '67-'73 time frame, you'll discover that the added wheelbase results in added rear seat leg room, meaning the floorpan stampings behind the front seat is where the wheelbase is compensated for, not in the front subframe/body area as mentioned. When looking at exhaust items for C-body Chryslers, that's when I determined this was what was going on as the front exhaust manifold lead pipes were all the same between Plymouth Fury, Dodge Polara, Chrysler Newport/300/New Yorker yet the pipes between the ball joint connection and the muffler were all different. Only reason for them to be different is the wheelbase difference between those cars (119", 122", 124"). Imperial bodies were longer in front of the front wheels and aft of the rear wheels, but that's just sheet metal hanging on the basic structure. One area that might affect the Imperials of the '67 era would be the isolated engine mounting structure that was unique to Imperials only that might affect some of the routing of the trans cooler lines. Where the engine and trans are would be the same regardless of the wheelbase and should have the same relationship to the cowl/firewall. If, as I mentioned, the fan shroud on the Imperial is longer than on the regular Chrysler C-body cars, that would mean the core support is farther forward on the Imperials, which has no relationship to the wheelbase specification. Just some thoughts, W Bell