sol_searcher

I have a 383 LT-4 built by Sunset Racecraft in 1997. It was a pretty expensive build at the time. It has about 1000 miles on it. I want to convert it to a conventional distributor for a number of reasons. I am using a speed density ECM off an early LT-1.

Since LT-1 Intake is no longer around, who can machine the LT-4 intake for a distributor?

What else do I need to do for this conversion?

I know about the EFI Conncetion 54x (sic) conversion and it is nice. But for the money I would just swap in a new LS-7.

Any assistance appreciated.

Rob94hawk

iTrader: (1)

It's EFI 24x and the price is ~2000. So I'd be really impressed if you swapped in an LS7 for that price. That's not including a new M6/auto which your current one is not compatible.

As for your situation any competent machine shop can pull it off:

http://www.96z28ss.cz28.com/photo3.html

sol_searcher

Thanks for the link. Still would like to know about ECM and how to wire in distributor.

Your right, it is not 54x it is 58x and EFI Connection's "Quick Quote" is $3130. Which is more than $10,400 for an new Chevrolet Performance Parts for an LS-7.

But the price for the 54x goes up. $150 diesel two round trips to a competent machine shop. Machine the manifold $150. Repowder coat the manifold $100. Intake manifold gaskets $35.00. Calibration and dyno time $500 and up. Now I'm up to $4085 for 58x. The 58X is a sweet system - but just don't want to invest another $4085 or more into the LT-4. Somehow I just feel that buy the time it is done it will nickle-and-dime me to close to $5k. At some point you stop investing in a one-year engine, like the LT-4. Lick your wounds and sell it off for pennies on the dollar (this was a $10k plus engine in 1997). The LT-4 was a bad decision for my application from the beginning.

I figure a simple distributor conversion would be close to $2000 - ECM, wiring harness, MAF, spark plug wires, machining intake, ECM tune etc. Beginning to doubt that I could even keep it under $2000.

Also, under no delusions that the LS-7 Swap will end up more like $17k to $20k. New radiator, engine front end, ECM and harness, all dry-sump hardware, custom built stainless headers, etc.

RamAir95TA

iTrader: (2)

You don't want the 58x, you want the 24x. I'm helping to install the conversion on a buddies car as we speak. He's got about $1800 into the conversion, start to finish, and we're just about done. AND we could have saved some serious $ had we gone with used parts or sourced parts elsewhere.

And remove the hyphen from the LT-1/LT-4. That's 1970s talk. This is the LT1/LT4 (no hyphen).

If you want to use a conventional distributor AND the LT1 PCM you've got some work to do. Honestly I would go 24x all day every day over the conventional distributor method. But from what it looks like you're doing (into a Jeep perhaps?) I would just go carb and call it a day. That would be much cheaper than what you're looking to do. The best part is there's no machining needed and all of the parts for the conversion you can get just about anywhere and do it in a matter of days.

purpleflamzz

Im running the lt4 intake set up for a distributor, and decided to use the fast ez efi multi port kit to run the motor so far i like it. my car is a 72 motor is a 396 stroker, so I dont need the lt pcm but yours will for the other items the pcm controls.
dont know if you will like the lt4 intake on lt1 heads the ports dont line up right.
just realized you have a jeep, cool set up look into the fast kit for multi its only 900 out the door.
you can always buy a pro comp intake and tb for 500 that will run with the sytem and already has the distributor set up in the rear. I'm looking in to this as well to swap away from the lt4 intake.
http://www.ebay.com/itm/SBC-CHEVY-10...sories&vxp=mtr

RamAir95TA

iTrader: (2)

You can still get the GM Performance dual plane carb manifold for the LT1.

sol_searcher

Thanks I have an LT4.

I will rethink EFI Connection conversion. Why do I want a 24x instead of the 58x? Has the experience with the EFI Connection conversion been positive? Are most people happy?

Rob94hawk

iTrader: (1)

Pretty much nothing but positive. If it weren't for the price I would have done it.

96capricemgr

iTrader: (1)

The LT4 intake has LT1 ports. The LT4 intake has more material above the port that offer material that could be used to port match.

Point being your super magical LT4 can easily use a lowly LT1 intake.

purpleflamzz

I thought the LT4 intake had raised runners that dont match up with the LT1 heads?
they even use a different gasket, it may fit but sure wouldn't flow well.
dont think I would use a LT1 intake on a LT4

96capricemgr

iTrader: (1)

The head ports are TALLER the floor is in the same spot, pics have been posted, it is well documented, but the ignorance persists largely because LT4 owners want to feel special.
The LT4 injected intake has LT1 ports the smaller late trapezoidal ports at that.
GIZMO put up the pics years ago and I have linked to them a LOT of times.

stevo9389

you want to do 24x so you are not forced to convert from a cable actuated throttle body to drive by wire. otherwise it is the added expense of a throttle body plus the pedal assembly

bufmatmuslepants

iTrader: (3)

Why do you want to do this anyways? If in 15 years you've only put 1000 miles on the motor, why invest in something that gives no real added performance except a better tune? Why not upgrade your heads/cam to a more modern setup like AI ported trick flows or stockers and wipe the floor with ls7s all day?