i have a lead on a 93 351w and i had a question about swapping the dist. it is a fuel injected motor and i want to run a carb. can i just go to autozone and pay like 40 bucks for a carbed dist off a older motor or do i have to pay the 300 for one of those msd ones. also are those msd ones really worth it. the motor will be mostly stock anyways

 

Being pre-'94, the engine isn't a roller cam. Therefore you should be able to run whatever '69-93 distributor you want. I suggest running a Duraspark II, I like them. Simple electronic ignition, all teh parts you need except some wires (not many) to connect the compenents. Any number of junkyard donors can provide the wiring but it's not hard to make your own with some crimp connectors. There are simple diagrams out there to be Googled, trucks and Broncos wire up just the same. All you actually have to buy is the distributor, ignition box, and coil. If you already have a newer style coil, it'll work just fine.
If at some point you decide to swap the ignition for an MSD box, MSD will sell you an adapter for $8 that will let about any MSD box you like plug directly into a Duraspark II distributor.
If you want to speed up the spark advance, places like Summit will sell you "lightweight" distributor advance springs for a whopping $3. I saw a writeup somewhere that detailed swapping the advance weights themselves around to tune the timing curve for various purposes. If you care to play with the vaccum advance, you can also buy adjustable vacuum advance servos.
The advantages of an MSD distributor is that they are a bit better made out of better materials. A bit more adjustable. And they're pretty.
The biggest advantage of a Duraspark setup is the availability of parts. Literally any parts store. Stuff breaks, sooner or later. MSD makes fine stuff, but it's not perfect, nor foolproof.It fails too.My local parts stores carry no MSD stuff that I know of. None. They can order it for me, usually a3-5 day wait at best. The closest parts store to me had a rebuilt Duraspark II distributor on the shelf for $65 when I needed one.