[poolboy]

hey hows it going
I seized the engine in my 2004 safari 2 days ago, hit a rock down a gravel road covered by snow and cracked the oil pan. I want to do a V8 swap, what is the best year of chev/gmc V8 that will fit my van seeing it has the vortec 4.3., also do transmission and tranfercase need to be changed with the V8 to work with the wiring harness and ecu form the V8. All info is greatly appreciated

Thanks

Poolboy

 

[Gary]

I would suggest a V8 the same yr or better.The engine has to come out via the bottom on the sub frame or you have to cut the rad support and make brackets later to bolt it back in.

 

[poolboy]

Ya I guessed the same year but isn't the 2004 chev/gmc a 5.3 not a 5.7 or will the 5.3 fit into my van?

 

[astrovan98]

Check with your local G.M. parts guy and see if there's a 5.7 engine that will work with your PCM. Around 2002 the Astro/Safari line switched up to the Gen III style of PCM. You may have to do some rewiring to make an older VCM work with a 5.7 engine. See the info below regarding the Gen 1 truck 5.7L engine, also known as the L31. Although, you can use a car engine instead of the truck version, but the engine management system will still be an issue.
I am in the final stages of completing a 5.3L Gen 3 LM7 engine (2005 Chevy Silverado 1500) into my 1998 Astro. It fits but it is tight. Reminds me of the small block V8's we put in the 60's Chevy vans to replace the inline 6 cyls.
CAUTION:The 5.3L swap is by far the best engine in the G.M. small block line-up, but is definitely an advanced project. It is not a weekend swap. Nothing interchanges, you have to get the matching transmission, and everything is custom fit and fabricated. Nobody makes adapter mounts for the Gen 3 engines.
--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

The Vortec 5700 L31 is a V8 truck engine. Displacement is 5.7 L. It is the last production Generation I small-block from Chevrolet. The cylinder heads feature combustion chambers very similar to those of the LT1 V8, but without the reverse-flow cooling. As such, the L31 head is compatible with all older small-blocks, and is a very popular upgrade. It offers the performance of more expensive heads, at a much lower cost. It does, however, require a specific intake manifold (a Vortec head has four bolts attaching the intake manifold as opposed to the traditional six bolts per head). The L31 was replaced by the 5.3 L 5300 LM7. The 2002 model year was the final year for the L31 5.7 L small block V-8 whose origins date back to 1955. The Vortec 5700 produces 255 horsepower (190 kW) and 330 ft·lbf (450 N·m) of torque. It is currently being produced as a crate engine for marine applications and automotive hobbyists as the "ramjet 350" with minor modifications.

L31 applications:

* 1996-2003 Chevrolet Express/GMC Savana full-size vans
* 1996-1999 Chevrolet/GMC C/K full-size trucks
* 1996-1999 Chevrolet Suburban/GMC Suburban full-size long-wheelbase SUVs
* 1996-1999 Chevrolet Tahoe/GMC Yukon full-size short-wheelbase SUVs
* 1999-2000 Cadillac Escalade

 

[wheels55]

I've got good news and it has nothing to do with Geico....

For over a year now I have slowly been converting my 2001 RWD Astro to V8. I have learned so many things. Found a totalled GMC Yukon with less than 100 miles on it. I bought the entire drivetrain from it. This consisted of a 5.3L (drive by wire) V8, its 4L65e transmission, drive by wire accel pedal and both the PCM & TCM. Mounting it was much more simple than one could have imagined. I bought the Jags That Run conversion V8 mounts for Astro/Safari that everyone talks about. I then bought some adapters that mate a newer LSx based block to old school V8 mounts. Everything mounted right up! Existing transmission mounts from the original Astro 4L60e worked. I didn't even have to modify the stock drive shaft! Left me with 8-10" between motor and radiator.

So far I have installed:
2007 5.3L DBW V8
2007 4L65e tranny
Precision Industries Vigilante 3000 Stall
Z06 cylinder heads
LG Motorsports G5Xe camshaft w/ Crane double springs
Performance Underdrive crank pulley
C6/Z06 massive electric cooling fan w/ Vette GM fan controller

In progress:
fuel system mod
under hood wiring
rear disc brakes
rearend posi unit

May have to swap a better rearend. We'll see. I don't plan on ever taking it to the strip with slicks but will treat every traffic light as a challenge to anyone who thinks it still has the 4.3L under it.

Questions you may have so far:
#1 How do you plan on getting the stock guages to work?
#2 How will the cruise control to work since the Astro was not DBW?

Answers:
#1 & #2 Found a guy named Jared at a place called Current Performance (http://www.currentperformance.com) out of Florida. This man has intimate knowledge of the complete electronic blueprints to modern GM vehicles. He told me that if I wanted the cruise control to work that I had to ditch the 2007 Yukon's PCM. Turns out that the `07 Yukon's cruise is handled by the Yukon's BCM. Not good. However, Jared said that a 2007 Trailblazer SS PCM would do it. So dumped the Yukon's PCM for the Trailblazer PCM. Jared is now building me a harness that will be plug and play to my engine, transmission and Z06 electric fan. He says all my factory interior gauges will work and my factory interior cruise controls will work! woo hoo

Exhaust should be easy and we think that some f-body headers should work.

I hope this has pulled a little mystery out of modern Astro V8 swaps.

Wheels55
:layrubber:

 

[Matrixx]

Hi wheels55

That's very good information to know for sure. Thanks for the updates, I would really like to see it when it's completed if you have any pictures of it, thanks.

 

[wheels55]

No problem.... going up to my bud's shop this evening. I'll try to remember to take the camera. This whole idea is his. He's a Go-Fast guy who gets 650RWHP out of NA Vettes on 93 everyday. It has his idea to build me something that I can get my wheelchair in/out of easily while still being comfortable and able to satisfy my daily need for speed. No, I'm not going to ruin it with ramps and such. Just going to remove the middle seat so I can easily pull my chair in and lock it down. If I need to take a family road trip, the middle seat can go back in. I have some sweet Boyd wheels to put on it and hope to switch it over to airbags to drop it when parked. For accessibility, of course! ;-)

Wheels
:layrubber:

 

[wheels55]

Who knows... I may like it so much that I end up pulling the 5.3L and stuff a built up LS3 in it!

:layrubber: :layrubber: :layrubber: :layrubber: :layrubber: :layrubber: :layrubber:

 

[groupsaya]

No problem.... going up to my bud's shop this evening. I'll try to remember to take the camera. This whole idea is his. He's a Go-Fast guy who gets 650RWHP out of NA Vettes on 93 everyday. It has his idea to build me something that I can get my wheelchair in/out of easily while still being comfortable and able to satisfy my daily need for speed. No, I'm not going to ruin it with ramps and such. Just going to remove the middle seat so I can easily pull my chair in and lock it down. If I need to take a family road trip, the middle seat can go back in. I have some sweet Boyd wheels to put on it and hope to switch it over to airbags to drop it when parked. For accessibility, of course! ;-)

Wheels
:layrubber:

oke:
So any updates?
I'm gathering intellegence on this swap, but a '97 AWD and a crate LS1

 

[wheels55]

Yes, actually I do.....

All wiring is ready to drop in. Took quite a while to get that wiring done and shipped back to me. Finally got the exhaust figured out. After many trials and errors, G8 GT Kooks Long Tube Headers fit like a champ. Just needed a small trim of drivers side motor mount. Passenger side just needed a small frame notch and box and 2" relocate of a brake line.

The good friend and expert that is doing this for me has had very limited time to work on my van but I'm patiently waiting....

:layrubber:

 

[astro355]

Any pics of the progress?

 

[Mr_Bowtie]

:goodpost: We demand PICS NOW!!!!!

 

[groupsaya]

What upgrades to the fuel system/pump are you going to do? Surely the stock pump can't supply the volume. Running an air fuel gauge so no lean melt downs?

No problem.... going up to my bud's shop this evening. I'll try to remember to take the camera. This whole idea is his. He's a Go-Fast guy who gets 650RWHP out of NA Vettes on 93 everyday. It has his idea to build me something that I can get my wheelchair in/out of easily while still being comfortable and able to satisfy my daily need for speed. No, I'm not going to ruin it with ramps and such. Just going to remove the middle seat so I can easily pull my chair in and lock it down. If I need to take a family road trip, the middle seat can go back in. I have some sweet Boyd wheels to put on it and hope to switch it over to airbags to drop it when parked. For accessibility, of course! ;-)

Wheels
:layrubber:

oke:
So any updates?
I'm gathering intellegence on this swap, but a '97 AWD and a crate LS1

 

[wheels55]

Sorry about the camera quality. Evidentally these pictures are too big for the message board because the right half of each is missing. I assume if you right-click and save each picture that you would be able to see it as a whole....

Wheels...
:layrubber:

 

[wheels55]

The fuel system will be last on our list. We'll probably datalog it with HP Tuners and if it looks good, to the DynoJet with the wideband.

:layrubber:

 

[astro355]

Shiny headers for the win!

What part of the world are you in? I'd love to run that van when you're done. :layrubber:

 

[wheels55]

Kooks Headers..... They are for a Pontiac G8 GT and two of the primary tubes (one on each side) had to be rerouted.

Dallas, TX area....

Gonna spray it too in the end, after the 9" rear goes in....

:chevy:
:layrubber:

 

[groupsaya]

The good friend and expert that is doing this for me has had very limited time to work on my van but I'm patiently waiting....

:layrubber:

...So are we...
That's interesting about the G8 headers fitting, though. Anymore updates?