I'm swapping my 1994 5.0 for a 1988 5.8. Just got the new motor yesterday.

Can I use my 5.0 accesory brackets and belt system? Can I use the 5.0 fuel rail and injectors?

 

Yes the belt from the 5.slow will be too small

 

Yes the accessory brackets will bolt on but you need a longer belt because everything will now be further apart.. the 5.8 block is wider. And because of that you can't use the intake, fuel rail, distributor, or oilpan from the 5.0, these parts simply won't fit on the 5.8. To fix the distributor issue either go find a late model 5.8 dizzy for the remote TFI setup and put a cast drive gear on it for the flat tappet cam in your motor, or take apart the 5.8 distrubutors you have, remove the TFI module, drill a hole for the '94 PIP wiring harness in the front of it and transfer that module from your 5.0 distributor, and then put it back together. I did this myself for my 5.8 build it's easy to do.
P.S Do not try to use any engine wiring that came with the donor motor, use only wiring that came in your truck.

 

Awesome! Thank you very much. I just stripped the 5.8 down to the heads and block. Broke a few bolts in the process :-/