350 swap questions

[Jerryred94silvy]

Hello everyone. I am in the process of swapping out my 4.3 vortec for a 350, and being that this is the first time I've ever done this, I have a number of questions that I need answered.

-Will I need specific motor mounts or will the v6 ones hold? (I know I'll need the mounting plates that bolt to the frame)

-This new(er) 350 is a '55-'85 motor so it has the two piece rear main seal crank. Which flexplate do I get? between the 153 tooth and the 168 tooth. I measured the TC and it was close to 12in in diameter does that mean I need the 168 tooth?

-Is the v6 starter too weak for this bigger engine?

-This engine is carbureted(that's how I got the engine and that's how I plan to keep it) so I need to make the transmission cooperate with this motor that won't be running on the original computer. I've read somewhere that you take some wire out of the distributor and run it to something somewhere but that's all I know(very descriptive I know lol).

And things like: getting power to the coil, making the gauges all work, and things like that.

Any and all help/advice is greatly appreciated! Thanks!

 

[kennythewelder]

Yes, the enginehas a split rear main seal. I think its the same, starter but not 100 percent on that. As for trans, what year truck are we talking about? The 88s were 700R4 trans. In 92 or 93, they went to 4L60E trans. This will need a trans controller ECM, and a TPS sensor on the carb to tell the trans when to shift, ECT. In 96 these trucks went to OBD II ECM systems, so they are even more complex to swap back to carb. Gauges have to be rewired so they will work. The speedo reads from the speed sensor in the trans, and that goes back through the ECM. A trans controller may, should have these capabilities, IDK. And the motor mounts will need to be for a 350.

 

[Jerryred94silvy]

The truck is a 94 with a 4l60

 

[PlayingWithTBI]

4l60 or 4l60E? The 94 came with a 4l60E, electronically controlled by the (7427 usually) PCM. As @kennythewelder said, you'll need a TPS.

 

[kennythewelder]

My 93 WT had a 4L60E. I think that was the first year for the E trans

 

[Jerryred94silvy]

Is there a way to make a tps work with an edlebrock carb? I've seen brackets for Holley carbs but I'd like to use what I have if at all possible. Also, for the gauges, would it be easier to set up some aftermarket gauges? Or wire the existing ones to work?

P.S- I really dig those hood stripes @kennythewelder

 

[kennythewelder]

Thanks, my truck is mint. You can make your gauges work or do a swap, its kind of up to you, what you want to do, and how much money you want to spend. Here are a few videos. It may also be worth contacting http://blackbearperformance.com/ and see if they can program a ECM just to run your trans, and gauges. IMO I dont see why a tune shop could not just tune out what you dont need, and just use your OE ECM to run the trans and gauges.

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https://www.youtube.com/results?search_query=5.7L+vortec+carb+swap

 

[kennythewelder]

P.S- I really dig those hood stripes

If you click on my avatar, then my albums page, then my 97, I have a lot of pics of my truck in there, if you are interested.

 

[Supercharged111]

Thanks, my truck is mint. You can make your gauges work or do a swap, its kind of up to you, what you want to do, and how much money you want to spend. Here are a few videos. It may also be worth contacting http://blackbearperformance.com/ and see if they can program a ECM just to run your trans, and gauges. IMO I dont see why a tune shop could not just tune out what you dont need, and just use your OE ECM to run the trans and gauges.

xc_hide_links_from_guests_guests_error_hide_media

https://www.youtube.com/results?search_query=5.7L+vortec+carb+swap

Clever? From the guy who can't properly pronounce the word "Edelbrock"?

 

[Jerryred94silvy]

Thanks, my truck is mint. You can make your gauges work or do a swap, its kind of up to you, what you want to do, and how much money you want to spend. Here are a few videos. It may also be worth contacting http://blackbearperformance.com/ and see if they can program a ECM just to run your trans, and gauges. IMO I dont see why a tune shop could not just tune out what you dont need, and just use your OE ECM to run the trans and gauges.

xc_hide_links_from_guests_guests_error_hide_media

https://www.youtube.com/results?search_query=5.7L+vortec+carb+swap

So far making the gauges and transmission function without all the TBI and sensor junk are the biggest visible challenges so far. I figured I could just pull the sensors for coolant temp and oil pressure off the old v6 and swap them over, but the holes that those sensors would go in the v8 are not the same size as they are in the v6. I'll look into the tuning route some more, I was really hoping I could use some of the v6 parts to make the engine talk to the gauges...I guess we'll see how that turns out though. And thanks for that video! Would I need that little black shift box that he had? Or would the tps just run through the existing computer?

Sorry for the barrage of questions(and potentially repeated questions). I'm learning all of this stuff as I go, and that's why I came to this forum