Will a Thunderbolt IV for a 4.3l work on a 5.7l?

Soonerfan51

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Hello, Does anyone know if a thunderbolt IV for a 4.3l will work on a 5.7? I am doing a 4.3L conversion to a 5.7l Vortec motor. Any help would be appreciated. Thanks -mark
 

Bondo

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Re: Will a Thunderbolt IV for a 4.3l work on a 5.7l?

Does anyone know if a thunderbolt IV for a 4.3l will work on a 5.7?

Ayuh,.... Just how much of it do you want to use,..??

The 350 will probably run Really Bad,... 6 sparks makes an 8 cylinder do that...:rolleyes:
 

180shabah

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Re: Will a Thunderbolt IV for a 4.3l work on a 5.7l?

...but it still revs to 5k on the muffs, why won't it plane????
 

180shabah

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Re: Will a Thunderbolt IV for a 4.3l work on a 5.7l?

Or will it provide a 25% increase in fuel economy?
 

Bondo

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Re: Will a Thunderbolt IV for a 4.3l work on a 5.7l?

Or will it provide a 25% increase in fuel economy?

Naaaw,... You'll be Saving a whole bunch of Sparks,...
But dumping Raw Fuel down the pipes....
 

Don S

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Re: Will a Thunderbolt IV for a 4.3l work on a 5.7l?

You can use the distributor, they are all the same, all you have to change is the cap and rotor. But you will have to get a 5.7 ignition module.
 

Bondo

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Re: Will a Thunderbolt IV for a 4.3l work on a 5.7l?

You can use the distributor, they are all the same, all you have to change is the cap and rotor. But you will have to get a 5.7 ignition module.

Ayuh,... Wouldn't it take Complete disassembly of the Distributer to change the reluctor wheel to 8 bumps,..??
 

Don S

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Re: Will a Thunderbolt IV for a 4.3l work on a 5.7l?

Ayuh,... Wouldn't it take Complete disassembly of the Distributer to change the reluctor wheel to 8 bumps,..??

Nope, it's part of the rotor. The sensors in the distributor are the same. Just the number of notches in the rotor passing the opening. And the number of wires in the cap.
Selling a person a V6 rotor when they have a V8 will drive them totally NUTS!
I did that years ago :eek:
 

Soonerfan51

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Re: Will a Thunderbolt IV for a 4.3l work on a 5.7l?

Thanks for all the replies. I am not a complete dumb***** I know the cap and rotor will need to be changed. What I am worried about it the module. I'd suspect it will power the distributor just fine but will the total advance be correct? What is the difference between the 4.3l thunderbolt modules and the 5.7l thunderbolt module? Thanks again
 

Don S

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Re: Will a Thunderbolt IV for a 4.3l work on a 5.7l?

Already answered that.

You can use the distributor, they are all the same, all you have to change is the cap and rotor. But you will have to get a 5.7 ignition module .
 

Soonerfan51

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Re: Will a Thunderbolt IV for a 4.3l work on a 5.7l?

Already answered that.

How about a little more specific of an answer? Does the 5.7l thunderbolt IV have a different timing curve? power requirement etc..??? Or is it just a different part #? Thanks
 

Don S

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Re: Will a Thunderbolt IV for a 4.3l work on a 5.7l?

It's a different part number. Even the manufacturer number is different. I've never actually tried to put a 4.3 module on a 5.7 to see what it does. Who knows, it may not even run. Give it a try, then let us know.
 

Soonerfan51

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Re: Will a Thunderbolt IV for a 4.3l work on a 5.7l?

It's a different part number. Even the manufacturer number is different. I've never actually tried to put a 4.3 module on a 5.7 to see what it does. Who knows, it may not even run. Give it a try, then let us know.

I'll give it a shot. I am thinking that the difference is the amount of total timing the module allows. Once I get it going I will hook it up to a digital timing light and observe the total timing and see if it is adequate. If not I will switch module. Thanks for the help.
 

gadget73

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Re: Will a Thunderbolt IV for a 4.3l work on a 5.7l?

Timing curve would be my guess. If it plugs in, I'll bet it will make spark but thats about all I can speculate. Recently I was talking with someone about the ignition modules. He replaced a 305 with a cracked block with a 383 stroker engine, and was having problems with it not performing properly. Long story short, he took it to a local mechanic who knew how the part numbering system worked and how to find a module with a different timing curve based on those numbers. I think he ended up with a module for a big block or something, but it happened to be the curve his engine needed.
 

Bondo

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Re: Will a Thunderbolt IV for a 4.3l work on a 5.7l?

Ayuh,... Somewhere, I seen a chart of the advance valves for the different part #s for the different modules...
Dennis Moore's book maybe,.?.?. or somewherein the Manuals,..??

Between the stock, lightly mod'ed, SBCs, BBCs,+ Merc. Racing motors,..
There's 6 or 8 or 10 different 1s available...

The V6 module is used on V8s, but only in Forced Induction motors...
 

Soonerfan51

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Re: Will a Thunderbolt IV for a 4.3l work on a 5.7l?

Ayuh,... Somewhere, I seen a chart of the advance valves for the different part #s for the different modules...
Dennis Moore's book maybe,.?.?. or somewherein the Manuals,..??

Between the stock, lightly mod'ed, SBCs, BBCs,+ Merc. Racing motors,..
There's 6 or 8 or 10 different 1s available...

The V6 module is used on V8s, but only in Forced Induction motors...

Thanks Bond-o
I am searching out a V8-22 Module.
 
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