Hi guys I am new to the forum and thought you guys maybe able to help me. I have just purchased a 1972 Dodge Challenger with a 318 and 904 transmission and I want to swap it out for a 383. From what I have been told all I need to do is buy motor mounts for a 70 challenger. They are saying the k member was the same. Has anybody else here done this before. Also will the trans crossmember bolt up the same? Where can I find a driveshaft that will fit cause I know the 727 is longer than the 904. Also do you think its worth swapping them out. The 318 engine that came with the car is bored .40 over but is a basket case and needs pistons, cam, lifters, gaskets, carb, etc. Where as the 383 is complete but I am not sure of the condition I bought it none running but turns over. Previous owner said it runs good and he seemed honest. Thanks for any help you can give me.

 

The K-frames are different between the two, but you can use the small-block one if you get the motor mounts & brackets from Schumacher Creative Services (http://www.engine-swaps.com/). You should be able to use a big-block trans cross member and driveshaft from any Challenger parts car- try any of the used parts dealers listed in Mopar Collector's Guide or Hemmings to get those.

 

383 is a darn good engine. Depending on year, in stock form it produced 335hp. It's a big block "B" engine, and uses a different k-member than the 318 (small block, or A-block) does. You can replace the K member, or buy the mounts Tom mentioned above. Also, as Tom already mentioned, find a parts car for the trans mount. Be prepared to give a body part for it though. Cuda and Challanger parts are very dear.

Be advised that in some cases the Schumacher engine mounts can be a bit of a hassle if you plan to use headers on the engine. The will be able to supply that info.

 

I have a 1973 318 car I have installed a 440 into. I did not have to change the cross member, just order new mounts for a 1970 440 car from mopar. Replace trans cross member and drive shaft. The radiator might have to be changed depending on the year of the engine because the inlet and outlets are swapped. I also left the small block torsion bars in because you will get better weight transfer. You will also have to find some e-body big block exhaust manifolds. I know when I did my car 6 years a go they where hard to find, so you may have to go with headers.

 

Well I found some motor brackets off ebay and looks like it will bolt directly to my cross member. I am trying to locate a radiator for it from a 70 ebody with a 383. I have ran into a few hurdles. Like the 727 that came with the motor is longer than the 904. So I will have to cut down my driveshaft. But I think it will be worth it in the end when I get to the point where it road worthy. But I appreciate your guys input. thanks again.

 

I don't know where this different K member stuff came from but it's bunk. You guys forget that Mopar did things on a shoe string budget and made as many parts interchange as possible. I'm not up on the later stuff but it wasn't until Mopar went to the spool mounts that there might be a difference in K-members but I wouldn't count on it. There are three basic K-member designs. Slant 6, V-8, and Hemi for B body cars.