jbander

If so what needs to be done.

Sacrilege

iTrader: (1)

You mean a carb conversion?

jbander

Thanks for the quick responce ,Sure if thats the only way.

LLLosingit

iTrader: (4)

This is to point you in the right direction, The actually part needed will depend on the heads you have (Cathedral or Rectangular) and the reluctor wheel you engine runs (24x or 58x) and or if you want a single or dual plain intake. Edelbrock Performer RPM LS1 Intake Manifold Kits 7118

Or you can run a distributer with HEI/Points/Mag or whatever you choose.
Chevrolet Performance LS1 Front Drive Distributor Cover Conversion Kits 88958679

VIP1

Why though? A computer is more tunable and gives more power, better fuel economy, and better emissions.

If you want a non-computer engine, use the older Chevy Small Block. There are plenty still out there and GM still makes them too.

Your two options are EFI or Carb.
EFI = computer.... although there was MFI in the past which is Mechanical Fuel Injection... meaning no computer, but that is rare and I'm not sure anyone makes that anymore. It wouln't be a direct fit for an LS1 either. You'd need a conversion just like if you went the Carb route.

jbander

I have a 355 SBC that I converted off of the computer now and the reason I did that is when I work on them I don't always have it in the back of your mind that the problem could be the computer that I know nothing about. I'm still open for anything and really thinking about a cam only nitrous setup. As of now.

RPM WS6

iTrader: (3)

Nothing wrong with doing a carb conversion on an LSx. Some folks will complain that it's dinoasaur tech, etc., but it does have its subjective advantages (especially if you're an experienced/advanced carb tuner and don't want to start over with EFI).

Plenty of power can be made with a carb, they are still building and improving these relics. But I agree that EFI will, on average, be more efficient over the wide range of conditions normally seen with a street driven vehicle.

Sacrilege

iTrader: (1)

But an MSD ignition box is still a computer.

RPM WS6

iTrader: (3)

You can do a front mount distributor conversion and use a distributor that doesn't require a box. Check out the second link in post #5.

jbander

Hey RPM I had a rare bird, 1970 Nova ss396 L89 . Long long time ago It maybe is the only one left for that year. Can't pin down the existing owner on part of it's history.

RPM WS6

iTrader: (3)

I've seen these discussed before, I think there were a few that popped up and were supposedly verified as original/real by experts at the time (maybe 15 years ago?) I think there was a black one, and maybe a white and silver one as well? I know there were also early '70s shop manual publications that listed block stamping codes for L89s in Novas (so they weren't exactly "off-the-books"), so who knows how many were actually built originally (maybe more than some folks realize).

Either way, that's a very cool car to have as part of your personal collection history. My understanding is that there was no power advantage to the L89 over an L78 - just that they came with aluminum heads. Is that correct?

lumen8

If you want to carb it with a single plane, you can use a ready to go control box to run the spark and use the factory style coils.. instead of going to a distributor.

https://www.holley.com/products/igni...rip/parts/6014

jbander

No Hp increase listed but the 375hp was a breaking point for insurance I believe at the time. They were rated at 430hp. My number that I remember is 6 l89 in the 1970 Novas. I bought the car from a motor head that worked for a Chev dealership. He only owned it for a few months and sold it to me , he wanted a vette. He gave it away to me, probably what he owned on it.
The key to it's value was in the fact that the Aluminum heads was listed in the VID , I don't think it was on the block number but I don't know. Last Time I checked into it there was one verified and one that the owner wouldn't verify to the public. I communicated with the verified one but he would only give me the latest history. I even had the window sticker that I passed onto the guy that bought it from me.
I have great story's about the car. Wild wild story's.

jbander

Someone above pointed out that that would just be trading a computer for another computer. What is everyone's thoughts on that. Thanks everyone , this is great information. Another thought the computer is wired to many different things are they basically not not wired(computer controlled) without engine function problems.

LLLosingit

iTrader: (4)

EFI and that MSD box have little in common, The MSD box only controls ignition timing and relies on 1 sensor and there is little that goes wrong with them. EFI on the other hand relies on multiple sensors and tuning is not as basic as a carb. Yes EFI is better but if a person knows how to tune a carb they really aren't sacrificing power. I know a few guys that went with the MSD box and a carb, They hid the MSD box and coils and then put on vintage style valve cover and air cleaner, If you walked by it at a show at first glance you wouldn't notice it wasn't a SBC.

lumen8

Yes this, well said ^

jbander, if you went with a carb on an older style engine you would probably be running some kind of MSD ignition box or similar anyway? What did you do on your SBC previously for the spark? ... the MSD box to run the LS is more or less the same deal as a SBC with an MSD 7 for example, unless you were comparing to points, or a magneto LOL.

Id prefer the LS coil set up with MSD box over a distributor and long leads, in part because putting a distributor on an LS is more work than plugging in the MSD, but there are more reasons. Although thats just personal preference. I guess, you could go all the way and put a dizzy on it... but I think for what you have in mind the MSD box would give you the least hassles.

jbander

I put a HEI distributor on my 355 and unplugged the computer..One more question If I may, If I keep the EFI how much of the computer harness needs to be plugged in, is it all needed to make the engine function with EFI?

jbander

Thank you LLLosingit.

lumen8

Do you have a factory LS harness (like out of a donor car) or is it a new aftermarket one?

If its a factory donor harness, yes there is a lot of junk you can remove.

Also is the loom from an auto or manual vehicle, and what gearbox will you be running? Potential to remove even more stuff off the loom there depending.