Apologies, I know there are probally a thousand threads on these topics but I am having trouble finding exactly what I need. I have the old 305 and 700r4 pulled from my 85 camaro, and I am looking to make around 320-350 horsepower with whatever I put back in whether that be the 305 or a 350, I am not picky on what goes in as I am capable of really anything besides fab and welding, mostly looking for something easy as this is my first time swapping an engine and not just RnR. I am keeping the 700r4, and this is going to be a cruise car with a little bit of extra power. Trying to keep interior as stock or stock like as possible. I could get my hands on an lt1 out of a 93 'bird and make power goals quite easy but i am wondering exactly how I would get Engine management to work, can i just plug an play the provided harness? Do i need to modify the harness I have? Is there a harness i can buy online? Or I could find an old 350 and rebuild that and get rid of the wiring harness completely. Need some advice and guidance, much appreciated.

 

First I'd ignore the hp goal. End of the day, the number itself is not that important. The actual performance is. Firat figure out your goals. Street only? Occasional race? Easy to drive like a stocker? More rambunctious? That sort of thing. How mechanically inclined are you? I don't mean which cars specifically but if you can learn, it takes the added cost of outside help which is harder and harder to come by. Makes a big difference on budget and on expectations. And then what's your budget bearing those goals in mind?
I'm guessing this is a carb car but if tpi my advice is a bit more difficult to use. My most basic advice with the general idea I get from your post is get a crate vortec 350 https://www.gmperformancemotor.com/parts/19432780.html and an intake similar to this https://www.jegs.com/i/JEGS/555/5130...xoC6h0QAvD_BwE. Put a GOOD exhaust, heads to tailpipe on it. Tune it in and drive. Very basic, big step up, easy to drive. Note there's ALWAYS a ton of ancillary things you'll either want to do or the project will force you to do. Like gearing. What's the axle have?
OR leave it alone. Look at the axle gearing only. 2.73 or something? Look to upgrading to a 3.23-3.73 range. (I'm personally more the type for 3.23 myself) Exhaust and gears will wake it up the most.
Leaving it alone has the advantage of not mucking up what may be already a good functioning vehicle.

 

by far the easiest would be to obtain and install a suitable 350 or 383,check the rear gear as suggested above ,and get it all going properly The '93 LT1 will give good results if installed properly,but that engine is a weird historical artifact these days and you might have to make some parts besides dealing with the electronics and fuel system...(LT1s are cool though ). A carbed engine can be done in '85 Camaro with no electronics or special wiring harnesses.

 

the goal for the build is to be a cruise car that can be taken to the track on the rare occasion. I am experienced mechanical wise, ive just never swapped an entire engine so I am mostly worried about wiring and not the mechanical aspect itself. The car is originally 305 TPI. so I am basically wondering if it would be easier to just switch to a carb 350 or switch to an LT1 (which i could get a 93 lt1 cheap but I am wiling to go find a newer version). the power goals for either of these motors will basically just come with the motor im sure so I am definitley not worried about that atm. My worries with the Carb motor are that I am for the most part totally inexperienced with carbs and my worry for the LT1 is how I get the wiring to function with the old car

 

Carbed engine still the easiest,but if you have access to all the associated parts(ECM etc.)for that LT1 it would be tempting to use it,and TPI fuel pump can be used.IIRC,stock '93 LT1 is 275 HP/325 TQ: plenty of power for a cruiser.

 

while the carb would be easier i can get this motor with the harness and ecm for 300 bucks cause my buddy is just trying to get rid of it, do you know if it is a basically just plug and play for that?

 

Wiring in an LT1 isn't plug and play. You'd have to rewire harnesses. And fab a place for the ecm or rewire it through the p/s fender like the original.
I love LT1s, I own 2, but I wouldn't advise it. I can't speak to why it's $300, but I have my guesses.

 

I mean is there a painless wiring harness I can buy to wire it up? Im not too worried about getting a bad motor from him as i know why it isnt in his firebird anymore.

 

What's your budget?
One thing to consider is a turnkey engine from GM.
One wire. One fuel line. More or less.
And a warrantied engine that looks to serve your goals.
As an example.
https://www.summitracing.com/parts/nal-19433034

 

I will second the suggestion of a Vortec-head 350 (L31). I used one for my project, swapped the cam and valvesprings and replaced the plastic timing cover with a single-piece aluminum part. Everything else bolted right up, including my exhaust, accessory brackets, and transmission. I should be making a bit over your power goals (the car is still in pieces so I haven't put it on a dyno yet).

I would steer away from an LT1 swap, as others have also suggested. I know it's tempting at that price point, but the nickels and dimes will add up. Unless you can get the entire donor car for a reasonable price, of course.

Personally in 2023 I wouldn't touch a carb unless I was building a race-only application. There are a number of proven aftermarket throttle body EFI systems out there which will give you better driveability and more tuning options, plus the ability to record logs (makes it a lot easier to identify issues and correct your tune). I modified my existing harness to work with a FiTech system, the most basic application is dead easy to set up. IIRC there were four wires I needed to splice in, and then I went back and removed unneeded wires for things like the diverter valve, injectors, etc.

Best of luck with your swap!

 

I would also recommend against any LT1, but most especially the 93. That was the 1st year and had all the usual "infantile design" problems, only some of which EVER got corrected over its (very short) lifetime.

The LT1 was a GREAT motor for its time. Arguably it took the SBC as far as it was possible to go without changing the valve angle. Butt it's a very "fragile" setup; not in the sense that it's "delicate" or prone to blowing up or any such, but rather, that even a tiny malfunction in something, causes MASSIVE issues. They're generally hard to work on and difficult to troubleshoot because the computer was so crood back then. The single strongest weeeeeeek point that it has is the OptiSpark: 1 tiny leeeek from the water pump, and you're into who knows what kind of expense and difficulty undoing what that inevitably does to the OS. Works great when it works; is a boat anchor when it doesn't. Plus, it was available for a total of, what, 4 yrs in Y bodies, 5 in F, a few in B (not sure how many) and few of those got it; and there weren't very many of any of those made in any of those years or for that matter in all of them put together. On top of that it was discontinued over 25 yrs ago. Parts are already getting hard to come by and are $$$$ when you find them. Just, altogether NOT a good swap candidate. Would have been pretty decent in 2000; in 2023, not so much.

I also agree that the all-around eeeeeeeezyest and cleanest swap, in 2023, is a 96-2000 truck 350, aka Vortec. As Bovine points out, it's a dead drop-in, except for the intake manifold, which can eeeeeeeezyly be worked around for either carb or FI. If your 85 is carbed, you can just slap a Holley 6210 on it (spreadbore man sec dbl-pump 4-bbl that accepts your linkage, fuel line, etc. without any adaptation) and go. Or, do the FITech thing, or Holley EFI, or MegaSquirt, if you want to go EFI. Simple to make work with your existing dash gauges and everything else. Just altogether the least effort you can put in, butt a MASSIVE bang for the buck. Measured that way, probably the BEST swap out there.

But in NO universe will the LT1 be the best choice. It will cost out the wazoo and cause endless headaches interconnecting its wiring with yours, and then be unreliable and unmaintainable over the long term to boot.

Spend less money and attention on the motor and more on the rest of the car. You'd be AMAZED at what a decent converter and gears will do. You'd also be AMAZED at how crappy your existing brakes are, especially if the rears are discs, and how much BETTER newer ones work. (which is hard to quantify until you have a before/after, but you can ask around on these boards for people's experiences) I'd suggest looking very carefully at LS1 both front and rear.

 

Listening in.