the LA-318ci Chrysler/MoPar Small Block style V8 engine is a wedge engine, in the LA engine family of 273-318-340-360ci with shaft style rocker valve-train {oil valve-train thru the rocker shafts}, many parts are interchangeable, very dependable, least warrantied engine ever produced, by any automotive mnfgr... the 5.2ltr./318ci Magnum is very similar, has the same bore & stroke, but with individual stud mounted style rockers, a little better flowing cylinder-heads & hydraulic roller camshafts, different type intake manifolds & 10 bolt valve covers, they also oils the valve-train thru the push rod instead of the rocker shafts, like the LA-318ci, the Magnum usually is equipped with a TB EFI too, both are great engines, there's also a 5.9ltr./360ci Magnum too... some parts are interchangeable between the 2 designs either the LA or the Magnum, you would need to do some research, to see all the different parts & changes needed.... The SBC 305ci Chevy/GM engine is the V8 base engine mass produced, very common used for 10+ years, it's in the same family of the common V8's 265-302-305-307-327-350-400ci engines used from 1955- just a few years ago, many parts are interchangeable, GM has now replaced that design by the LX &/or LS designs, it's also a wedge head design GM corporate engines, like the earlier Chevy/GM Small Blocks it has a similar design/size/shape to the LA-318ci & 5.2ltr. Magnum Chrysler/MoPar engines, but they are completely different mnfgr's & nothing will interchange....