Hey guys. I removed and am selling the carbed 350 out of my 87' Formula and am contemplating an LT1 swap. I can get a real good deal on one local so I've been reading everything I can get my hands on about the LT1 into 3rd gen swap to see what I need to do. Now, my main question is, everything I've read is about people using the stock harnesses and splicing em together, but what about using a custom one, like Speartech's? I read somewhere that even with the custom ones you still need to splice in 4-5 wires, anyone have a clue to what those are? Also, how much of the wiring do you need to go inside for? like under/ behind the dash, seems like most of it is under hood. As far as fuel goes, I'll probably end up running a TPI pump, but would I need the whole setup (sending unit, etc) from a fuel injected car seeing as though mine was built carbed and had a mechanical fuel pump? This was my first carbed car so I don't know much about em. My last question is more of an opinion thing, but what way did most of you run the fuel lines and hook em up? or what in your opinion is the best way? I mean as far as what type of line (stock, rubber, braided, etc) and how you connected it to the fuel rails (weld AN fittings on, use rubber, etc)? Yes, I have read plenty, so if any of this is repeated stuff, I'm sorry, but I think I may have been over reading and got lost. Thanks in advance for any help!!!

Believe it or not, your car had an in-tank electric pump as well as the mechanical on the engine. But, it was different than the EFI pumps, so you might still have to modify or replace the pick-up unit for an EFI pump. Getting a good used EFI pick-up shouldn't be a big deal, though.

I'll leave the rest of your questions to the more knowledgeable LT1 swap guys.

The wiring isn't that bad if you dont already have the speartech you could get a harness off Hawk's, eBay.... Most of the wiring is going to splice in to the bulk head not a whole lot inside. For the fule lines you will need some hard lines from a FI car or I have seen one swap with the braided lines run from the tank up.

Thanks for the info on the pump/ pickup 5-7. I think I'll end up grabbing the whole unit out of a TPI car just to be sure. Nice to hear that about the wiring, lol. Thanks chevyowner for clearing that up. I already looked at the braided, sounds/ looks awesome, but I don't know if I could swing it right now. I'll prolly just run the hardlines and use those adaptors I've seen around. Does it matter if the lines are out of a TBI car or do I have to get em off a TPI car? TPI stuff isn't too plentiful around here, but TBI stuff is. Sorry if they're the same, don't know much anything about TPI cars. Only had TBI and carb.

It would be best to use the entire hardlines from a TPI car, it puts them on the correct side of the engine.