Got questions?

We’ve got the answers—the Summit Racing tech department tackles your automotive-related conundrums. This week, we’re cramming a 383 into a 1974 Dodge Dart Sport.

Q: I have an old Chrysler Newport with a 383 and a 1970s Dodge Dart Sport with a 318 and four-speed transmission. I would like to put the 383 in the Dart to pump up the horsepower a little bit. Will the K-member from the Newport fit the Dart? If it won’t, what vehicle’s K-member will work?

Also, the Newport has an 8 3/4-inch rear-end. Will this fit the Dart, or will I have to modify it to fit? I would like to use the Dart’s four-speed with the 383. Will this work?

C.B. Oshkosh, WI
side view of vintage dodge dart running down dragstrip track
(Image/Sick The Mag – Wes Allison)

A: A 1967-69 A-body/big block K-member would work for this swap. As for the Newport 8 3/4-inch rear-end, it will have to be narrowed to fit the Dart. If you want to avoid that, you need to locate an 8 3/4-inch from another A-body. Depending on what year rear-end you find, you may have to have the axles re-drilled to a 4 1/2-inch bolt pattern.

There are two problems with using the Dart’s four-speed. The most obvious is trying to make the clutch linkage work. You may have to do some fabricating. The second problem is that Chrysler engines that originally came with an automatic transmission (like your Newport’s 383) do not have crankshafts drilled for the pilot bushing. Any competent machine shop can drill it for you. You will also need a big block bellhousing.

In our opinion, an automatic transmission would be a lot easier and less expensive. You will need an A-body automatic transmission crossmember and a driveshaft from a 340 Dart with a 727 transmission, or you can have the Newport’s driveshaft shortened to the proper length.

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Author: David Fuller

David Fuller is OnAllCylinders' managing editor. During his 20-year career in the auto industry, he has covered a variety of races, shows, and industry events and has authored articles for multiple magazines. He has also partnered with mainstream and trade publications on a wide range of editorial projects. In 2012, he helped establish OnAllCylinders, where he enjoys covering all facets of hot rodding and racing.