I want to put in this 350 TBI instead of the old 305 4 barrel. Wondering if anyone else has done it and what some problems or mods that I may runn into or need to do.

 

I do have all the wiring out of the truck the engine is comming out of so I can always tear it out

 

the wiring is a good start. your factory fuse box will not have all the fuses you need for the new setup, so you may need to make your own or modify the one in there.

the fuel lines will not be correct for the tbi setup, so you'll need to figure out if you want to modify what you have now (need flared & threaded ends, different side in engine bay) or if you want to just get replacement ones. sending unit will also have the same issue; everything is clamped on the carbed vehicles and not threaded fittings.

 

moving this to engine swap forum. Although this could be mostly wiring-related, you're still more likely to get the answers you need from that forum.

 

Have you considered putting the carb stuff on the 350? The would be a whole lot easier, and arguably a better end product.

Either way, the 305 exhaust is a severe restriction - even more so to a 350.

 

You'd have to build a stand alone harness to support the truck TBI PCM, or swap in a dash/engine harness from a 3rd gen equipped with the LO3. The latter would require a custom ECM tune still. Im all for dumping dated technology, but carbing a L05 is about the simplest thing you can do for easy, cheap power over your 305. Id hold out for a newer more powerful engine if I were you and not waste time on the old truck motor