Project MULE - 350 Vortec Tuned Port Injection build on 91 Suburban.

[Fast355]

Any idea what year Nissan Ultima fans you used?

That was two condensor fans combined in the same housing. I want to say 1997-2004ish have similar fans.

[Fast355]

Gheez man that's insane in that video to take off like that!

I am geared at 4.56 with soon to be 35s so that will mathematically put me back at stock (235/75-15s with 3.42)

Fast 355 you are giving me some good info on this build. I was starting to doubt my plan with other still yelling BIG BLOCK BIG BLOCK!


Aside the 8 injector connectors is there anything else I need to pillage from this 7165 harness? I have the entire harness including the under dash harness.

It ran really strong, strong enough to kill several 700r4 transmissions.

Not really that I can think of except the TPS and IAC connectors and cut them with ALOT of slack. Depending on the EGR solenoid type your TBI truck has, you may need the EGR connector.

One thing you will need to do is move your serial data pin on your ALDL connector to the lower row (IIRC Pin M) for use with the 8192 baud rate scan tools. Took me multiple hours to find out why I could not get data from my 7427 when I swapped back in the day.

[Six_Shooter]

So where do I get this third yellow ecm connector? Wouldn't I have to run this thru the firewall ?

As mentioned any donor vehicle that uses the '7730 and similar (3 connector) ECMs.

No, the wires needed for this connector get moved from the other existing connectors. GM decided to move wire functions around when they went to this ECM. I've already mentioned the extra wires that will be needed, IAT/MAT, since you don't have one currently.

I've made '7747 to '7730 harness adapters without adding any extra wires through the firewall, I did not use the MAT sensor in this configuration, but it was more proof of concept than what would be left in place. So most of the wires you need for the '7730 are already in the existing harness.

[Fast355]

As mentioned any donor vehicle that uses the '7730 and similar (3 connector) ECMs.

No, the wires needed for this connector get moved from the other existing connectors. GM decided to move wire functions around when they went to this ECM. I've already mentioned the extra wires that will be needed, IAT/MAT, since you don't have one currently.

I've made '7747 to '7730 harness adapters without adding any extra wires through the firewall, I did not use the MAT sensor in this configuration, but it was more proof of concept than what would be left in place. So most of the wires you need for the '7730 are already in the existing harness.

I added the MAT, but did not use the EGR so I stole its wire.

[pma4x4]

Well the engine still has to be built, I still have to rework or buy new heads. this swap wont be going down until December. We have a cross country trip in October and it would cut it close for having the motor done and wired and burned right before then. so until then its gather intelligence, learn lots, raid some yards this summer.

[pma4x4]

Hey Fast355, are you using just L31 heads on a regular old gen 1 block or is the block a L31 "880" block? I ask because I am trying to figure out the issue on double roller timing chains and the itming cover on the L31 block.

[Fast355]

Hey Fast355, are you using just L31 heads on a regular old gen 1 block or is the block a L31 "880" block? I ask because I am trying to figure out the issue on double roller timing chains and the itming cover on the L31 block.

It was a GM 20270 HD 350 TBI crate engine. It is an 880 block but was built as a 8.75:1 350 TBI.

Single roller chains works great, no need for clearancing for a double roller.

[pma4x4]

Ive just always done double and with the torque this thing is looking at putting out double was even more on my mind but your motor is living proof that a single is just fine. I am just adding up the parts list this weekend. Its not going to be cheap but its going great!

[Fast355]

Ive just always done double and with the torque this thing is looking at putting out double was even more on my mind but your motor is living proof that a single is just fine. I am just adding up the parts list this weekend. Its not going to be cheap but its going great!

The factory single roller chains are plenty strong. They come in the ZZ4, ZZ383 and a version also comes in the LT1 and LT4 and drives the water pump as well.
The factory rev-limiter on the LT4 was 6,399 rpm. With the capability to turn 6,400 rpm + water pump drag I think there is plenty of additional strength in the timing chain for a more basic small block. I have seen 7,000+ RPM LT1 engines running close to .600 valve lift and 450 lbs open spring pressure running stock LT4 timing chains.

[pma4x4]

Ya see right there? thats just good straight logical info! ZZ4s and LT1 and 4s handling a single chain then good enough.

[pma4x4]

I know when you burn a prom you can get rid of vats and stuff but can you burn and remove the EGR?

[EagleMark]

Sure!

[pma4x4]

Ok, I thought so I just wanted to make sure. I found out emission test only opens hood to pinch off evap system to check tank pressure (or what ever it is. Great, I can eliminate the EGR, Besides you can't see the EGR valve under a TPI anyways.

[Bigdav160]

Good luck with your project. I love my Burb. It's getting a similar build up. I rebuilt the axles and installed elockers, rebuilt the transfer case with added twin stick controls, built and installed a 4L60.

The engine started out as low mileage 880 L31 that I scavenged out of an conversion ambulance. (4 bolt mains, steal crank, powdered metal rods, roller cam). I installed flat top pistons and a comp cam 268XFI cam. I used the vortec heads on another project so I bought some chinese aluminum heads. The intake is Holley stealth ram with 58mm throttle body (I hope it's not too big). The fuel rails are also chinese eBay specials. 36lb injectors fed by a Walbro 255 pump.

For engine management I decided to go microsquirt. It'll be my first venture into tuning via software. It should be running in the next couple weeks.

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[Fast355]

Good luck with your project. I love my Burb. It's getting a similar build up. I rebuilt the axles and installed elockers, rebuilt the transfer case with added twin stick controls, built and installed a 4L60.

The engine started out as low mileage 880 L31 that I scavenged out of an conversion ambulance. (4 bolt mains, steal crank, powdered metal rods, roller cam). I installed flat top pistons and a comp cam 268XFI cam. I used the vortec heads on another project so I bought some chinese aluminum heads. The intake is Holley stealth ram with 58mm throttle body (I hope it's not too big). The fuel rails are also chinese eBay specials. 36lb injectors fed by a Walbro 255 pump.

For engine management I decided to go microsquirt. It'll be my first venture into tuning via software. It should be running in the next couple weeks.

Don't see the 4L60 being very happy with the setup, but feel the short block is a solid foundation for the power the heads/cam/intake will give you.