Block casting number is a pretty good indication. Pull a valve cover, if they are pedestal style rockers, Magnum, shaft style, LA.

 

What does the intake look like? Valve covers should be 10 bolts vs 5 on LA style.

 

I remember when I was thinking about buying a new truck back in the day, the Magnum engine was introduced for 1992. There was a left over '92 on the lot with MAGNUM across the windshield. I eventually bought a '93 that I saw them backing off the carrier when it was delivered. I'm pretty sure the Magnum was introduced on all V engines that year. Since they were so different, I can't see the logistics of carrying both types of engine in inventory.

 

More questions!! OK this is a 92 5.9 Magnum with a throttle body and I'm gonna convert it to a carburetor...Im gonna pull the motor down and freshen it up a bit...I was thinking of adding a mid-range cam, High volume oil pump, windage tray, Double roller timing chain, and gears, Can anyone help me with a good intake manifold and carburetor? Also, I'm going to convert it over to HEI ignition system also...long tube header...looking for suggestions!

Thanks for all your help!
P.S. I am a ford truck guy by nature and wanted to do a Ranger 5.0 conversion but found this rust-free 1988 Dakota and fell in love! LOL

 

Where are you looking to build power? If you want bottom end grunt, then a good dual plane 4bbl intake will be what you are lookin' for. Watch the bolt patterns though, most of the carb manifolds are for the LA engines... some will be drilled for both LA, and Magnum.