91dime

Not a 3rd gen project but its GM. I just got a late 70s c20- without an engine or trans. I have an early 90s 350 on the stand in my garage. The engine is complete, but the harness was cut when it was pulled. I have access to a mid 90s 5.7 Chevy that's totaled. I will be able to pull anything I need from it. I would like to keep the tbi "stand alone". My questions now are;

I have dual tanks in the truck and would like to keep them. Is there a good external pump/filter setup for tbi?

Will I have problems with the donor truck if it's an obd2? Will the engine harness be tied into a body control module, and make it very difficult to isolate?

Should I ditch the tbi and go to carb?

Thanks for any help/advice!

91dime

Before anyone answeres, I have found all the answeres to my questions. Mods can delete this If wanted to.

91dime

After getting the engine, I have found out the harness was not cut, but the ecu is long gone with the truck. I have no way of how to identify they exact year of the truck. Talking with some guys on a squarebody forum, they believe I need a 16147060 pcm.

The donor truck was a automatic 2wd, the c20 I am dropping it into is a manual. I assume the donor truck had electronic transmission control. Will I need to have a chip burned to get those controls removed so Iwont have a SES light on all the time?

91dime

Here's a pic of the plug to the ecu,

RBob

iTrader: (1)

The connectors show that it uses the '7060 PCM. Used from '91 through '93 (maybe '92?) with the 4L80E transmission.

Yes.

RBob.

91dime

So the 7060 will work with the manual after being burnt? Does anyone on here do that, or will I need to find a shop to do it?

I've megasquirted a few vehicles so I'm not afraid to give something a try. I just don't want to invest a lot of cash into burning tbi stuff because I won't do that much of it. Are the modifications I need done easy to do?

RBob

iTrader: (1)

The other thing you can do is to find a '7747 ECM and use it. The two tan connectors can be used with some mods to the 'keys' on it to allow them to plug into the '7747.

However, you will need to re-pin the connectors to match the '7747 pin out. They are different so don't mod the connectors and plug in a '7747 without re-pinning. Unless you like smoke shows...

There are many stock PROMs for the '7747 that match the truck engines.

RBob.

Formula-Finatic

So from what I've looked into with having a chip burned unless someone here is going to make you a screaming deal which happens time to time getting a chip made for the truck and not have the ses light from the trans is going to be an investment. Less than a standalone but I'm doing a a similar setup in a 74 short wide and have with an l05 from some truck that we scrapped sitting around we will get the truck on the road pretty cheap. The truck is to be used as a parts running truck for our shop so we decided that we were better off finding the trans that the computer matched from a wrecked 92 Silverado 1500 and the trans mounting fixings. Now all we have to to is weld up some brackets and were set maybe a custom driveline but haven't bothered looking that far since we're still getting the engine in and routing the harness. The reason we opted this route was we didn't have to pay for a burn, we figured best fuel economy running a 74 on 92 running gear, and having driven a 92 before it's a pretty reliable tourqy setup. The obvious downside being that trans isn't as durable as other choices but since we already have a designated truck for towing we don't mind. Now you mentioned you don't have a computer yet so you have a few options whether or not you want auto or stick. Since your truck is a 3/4 ton you may be wanting that durability when I called around to local shops for a custom burn I was looking at about 500. I got everything I needed for about $150. So just an idea

91dime

I think what bob suggested is what I will do. I am in contact with a guy who is going to sell me a complete 747 harness and ecu for a deal. He does have the external ecs, so I will have to source that somewhere but this seems like the easier and cheaper route.

I have contacted a few shops who burn chips, but none have said they can do what I need. And the one that will, eill charge a ton like you mentioned formula. I will either go 747 or back to a carb.

Tuned Performance

iTrader: (92)

Just a FYI the 92 k truck used the 16146299 a one year only ecm.
The 747 ecm will replace the 299 ecm no repinning needed. The 747 can be found on eBay for very cheap price. Just check the broadcast code 4 letters to see if it has a 350 700r4 calibration.

91dime

That truck could of very well been a 92'. Is there any way to tell by the harness?

Tuned Performance

iTrader: (92)

I think the only way to tell what the Harness came on would be to look at the ecms prom broadcast code.

91dime

Bob,

I am currently running a Q jet on the truck with an HEI. I have a complete 747 harness and ecm. Will I be to use my HEI with the 747?

Tuned Performance

iTrader: (92)

If it's s computer controlled hei yes, if not you need a hei coil in cap or divorced coil.

DanBrown

I'm currently putting a TBI unit off a 1995 Chevy 5.7L on a 1974 Chevy K10 5.7L. I am using a 16197427 ECM and made my own wiring harness, in lieu of paying Painless Performance 400 bucks for a harness. If anyone on this forum has done this type of swap, I'd like to hear from you for some help I need. Thx a lot.

Tuned Performance

iTrader: (92)

I have a 77 k20 with duel tanks and Holley Projection.
i plan to convert it to a closed loop and iac system in the spring using the 87-91 tbi 1227747 ecm.
you might look at the 87 c/k throttle cable and I’m not sure what transmission you have but if you have s th350 look at y-754 transmission cable.
larrys electric has the tbi harness for $275

DanBrown

I'm using a Muncie SM465 manual transmission with a Jags That Run VSS that drives thru the speedometer cable.

Tuned Performance

iTrader: (92)

Not sure how much you paid for the Vss but here is another choice.

https://www.tpiparts.net/inc/sdetail/7586

DanBrown

I've had it for several years and payed less than 100 bucks for it.

91dime

Edit: found the answer, it is not able to.

This is off topic, but rather than start a new thread Ill ask here first. I got rid of my C20 and got a K2500, and I have built an L31 with a Nv4500 to drop in it. I want to use the TBI still, but I put a hotter cam in and I would like to run headers eventually so I dont think the stock ECM is going to work well. I have a MS1 on the shelf I have modified for TPI/TBI. Does anyone know if I am able to use the MS1 and control the IAC with TBI? I know with TPI you can not.