Efi to carb swap

[87gmc512]

so I have a 1987 gmc and I'm going to to put headers, edlebrock intake and a 600 fm carb. So my question is, what all needs to be done besides eliminating all the emissions? And also what electrical needs to be stay and go? If I'm missing anything else please feel free and let me know

 

[Jrgunn5150]

You need a fuel pump that will supply the appropriate 7-8 psi to a carb, and a way to control the transmission lockup, although it will run without it.

 

[87gmc512]

New fuel pump or regulator? Also can I use a intake for just any small block? I have one I was gonna use off of a 86 Monte Carlo

 

[Jrgunn5150]

New fuel pump or regulator? Also can I use a intake for just any small block? I have one I was gonna use off of a 86 Monte Carlo

A new pump would be best, but I used the old pump with a regulator for like 18 months. The regulator I used had a hard time cutting the fuel pressure down enough though and gave me fits with my carb tuning.

Any small block intake will work, one from an 86 Monte Carlo might need the middle two bolt holes slotted, no big deal.

 

[87gmc512]

So when I do away with all the wires everything will work fine still beside fuel pump and trans?

 

[87gmc512]

Because a 87 is all ran off the computer right?

 

[Jrgunn5150]

AS far as I can remember, I cut mine out of my 87 like nine year's ago, but from what I remember I didn't keep anything from the ECM harness.

I'm pretty sure I did swap distributors at that time though.

 

[87gmc512]

So after I swap all that stuff out I can do away with the computer?

 

[Jrgunn5150]

Yeah, it doesn't run like your headlights or anything, just the throttle body.

 

[87gmc512]

So what do iuse for the the lock up? I have a th350

 

[Jrgunn5150]

So what do iuse for the the lock up? I have a th350

Oh, I had a 700r4, I don't think you have lockup. Some trucks got it, I'm not sure, sorry.

 

[yevgenievich]

some th350 had lockup too. In that case you would need to run a lockup set up from earlier year trucks that ran off vacuum. Or leave it unplugged.

 

[74 Shortbed]

The "TH350C" was a lockup, easy way to find out look for an electrical connection on the side of the case just above the pan just like a TH400 kickdown. If you don't want to go though the trouble of installing all the factory stuff, you can just hook it up direct on a toggle switch, you'll just have to remember to flip the switch before you come to a stop or it will kill the motor..

 

[87gmc512]

Can I just buy a stall converter ?

 

[74 Shortbed]

No, a non lockup converter will not fit, but you don't have to use the lock up if you don't want to.