What do I need to swap an LT-1 350 from a 1993 Trans am into a 74 Chevrolet Chevelle?

[LT-1/74Chevelle]

I have a 1974 Malibu Classic with a 350 built TH350 trans and 373 gear stock rear end. I have a whole 87,xxx mile LT1 350 1993 Trans am to pull parts from. It does run and drive but 3rd gear on the trans is smoked. I'm looking to use just the engine and whatever else I need to swap the LT-1 into my chevelle. I'm trying to use the same trans and as much as possible on the chevelle and leave as much of the trans am as I can. I do have a fuel cell with a sump and I plan on using an external fuel pump. I've heard that the LT1 bolts right in as long as I don't keep the ac which was the plan anyway. What my question is is what do I need for a harness and pcm to run this engine with the TH350 trans? And what else may come up during this swap that I haven't covered?

[firebird_1995]

If you are wanting to stay efi, you would be money ahead to convert it to a 94-95 pcm. The 93 is expensive.

[LT-1/74Chevelle]

What all do I need to do to convert it to a 94 PCM?

[SSlowBoat]

What all do I need to do to convert it to a 94 PCM?
Easiest would be a 94 harness, or a painless lt1 hotrod harness, a computer, 94 injector and fuel rail and intake assembly, and the 94 sensors

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[Injuneer]

On the other hand, the 93 ECM doesn't control the trans, so life is simpler in that respect.

[firebird_1995]

When you get a harness, if its from an auto car, just tie up any transmission connections or get rid of them if you're positive you'll never run a computer controlled trans again. Program the pcm for a manual transmission and you're golden.

[LT-1/74Chevelle]

I currently have the whole car so ill take that idea up with my 93 harness. Thank you

[LT-1/74Chevelle]

If the 93 PCM doesn't control the trans, then why does it have to be reprogrammed to think its for a manual trans? Sorry if this sounds like a stupid question, I'm just a little puzzled as to why

[zooguy]

if you go the 94 PCM and harness way ... i have pulled mine out cause i am going carb

[Injuneer]

If the 93 PCM doesn't control the trans, then why does it have to be reprogrammed to think its for a manual trans? Sorry if this sounds like a stupid question, I'm just a little puzzled as to why

If you go with a 94 PCM as he recommended, the 94 does try and control the trans. Reflashing as a manual eliminates the codes and consequences.

[popo8]

If hes gonna leave the motor stock and not require extra tuning... he can use what he has...

LTXtech.com IS my drug...
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[383z]

I agree with Popo.

[firebird_1995]

Yea, where the 93 gets expensive / involved is the tuning. If he's got everything available and it works, by all means run it. It will at least get you started. Then later on if you decide to do some mods you can weigh out changing pcms vs buying the stuff needed to tune the 93. Good thing is, if you've got a working 93 pcm, you can pretty much break even on the conversion and possibly end up with a little bit left over

[LT-1/74Chevelle]

I plan on staying stock with just headers for now. Thanks everyone for the info. I'm going to plan on using the 93 harness and pcm for now and upgrade whenever my TH350 decides to give up.

[383z]

Your TH350 should last a awhile. The lowest rated TH350 is rated at 410 lbs/ft torque and the 93 Camaro LT1 produced 325lbs/ft.
I think it depends on how bad you beat on it obviously.
What would you get if it goes out?
I would get a 700r4 for overdrive and you still won't need the computer to run it.

[LT-1/74Chevelle]

I still have the 700r4 that was in the 93 trans am since I have the whole car and its running. It'll just need a rebuild since 3rd and 4th slip. That's probably what ill go with once I get this conversion done and I have an opportunity to rebuild it.

[LT-1/74Chevelle]

Does anyone by chance know what headers I can use with the swap? I'd prefer long tubes

[Injuneer]

If hes gonna leave the motor stock and not require extra tuning... he can use what he has...

LTXtech.com IS my drug...
OWNER/ADMIN

+1

Keeps life simple, until it's time to tune it.