1973 C20 Turbo 5.3

[Gen3 Cheyenne]

Greetings to those out there. I'm nearing completion of my 5.3 LS install with turbocharger. I wanted to share a few things I've learned (the hard way) through trial and error. Below is a quick summary thus far.

2002 5.3 salvage motor (88k miles)
1996 4L80E trans - w/billet 10.5 RevMax 2500 stall
Nook & Tranny - Flexplate
PSI PCM computer tuning
Dirty Dingo LS Engine brackets
Just Chevy Trucks - turbo manifold and cross over pipe (designed for newer Chevy trucks, not mine)
GT45 Turbo (DNA motoring)

My truck is a 1973 C20 Cheyenne. I removed the original 454 motor and TH400 trans. I wanted this new install to retain AC and be 100% daily driveable. Not an all out drag vehicle.

First lesson learned - The Dirty Dingo mounts fit fine for the 5.3 in a C20 truck. HOWEVER... To fit the AC compressor, the motor MUST be positioned as far forward in the mounts as possible (towards the radiator). These brackets allow for more travel rearward (towards the firewall) but the brackets will then cover the area for the AC bracket. The biggest problem is in regards to the trans mount location. Using the 4L80E trans, the crossmember needs to be moved back about 1.5". Requiring much drilling of the frame. The C20 has several mounting locations for the upper and lower brackets on the frame. Royal PIA. In addition, I will need to have my 2 piece drive shaft shortened to fit.

Second lesson learned - The factory 5.3 truck manifold used on my turbo set for the drivers side is VERY tight and close to the frame rail. While it does fit, I will need to clearance the frame a bit to make sure it doesn't touch with vibration. The Just Chevy Trucks turbo manifold is sweet. Very high quality. The down side is that it has no wastegate provisions. Still trying to figure this one out. One additional problem will be routing the turbo downpipe. It's extremely tight to squeeze a 3" tube down by the firewall and underneath. I think it's possible, but the muffler shop will need to be creative. Or I will need to dump on the opposite side of the frame rail.

If you end up using the Just Chevy Trucks turbo kit, you will also need to use a narrower radiator (19" Width). My factory radiator outlets interfere with the turbo inlet. No room for piping. So I had to order a custom Griffen unit that could handle my expected power output. (PLEASE keep in mind that this kit was designed for NEWER Chevy trucks and works perfectly for them. I fully understood the potential issues with using it in an older chassis. But I wanted a turbo. Just want to be clear that it's NOT the fault of Just Chevy Trucks. They are awesome.)
Attached are few pics for those interested.

Hoping to have it running in next few weeks.

[bake74]

     Welcome to the site from California.  Since you are at this point, what would you do different ?  Are your inner fenders going back on ?

[Gen3 Cheyenne]

     Welcome to the site from California.  Since you are at this point, what would you do different ?  Are your inner fenders going back on ?

Greetings from California as well. I'm in the Northern Cal area.

When I started the project my hope was to be a plug and play operation. Bolt in, hook it up and I'm on my way. However, the turbo complicated things quite a bit. As well as the 4L80E. Hindsight I probably would have gone 4L60E (built stronger) and I could have saved the crossmember/driveshaft mods. Dirty Dingo makes a nice AC relocation bracket arrangement and I could have called it a day using the bracket adjustments. But I had already invested a boat load in the trans and custom converter. Oh well...

As much room as the 73-87 trucks have under the hood, there are still many limitations to certain swaps. The newer Chevy trucks have a pretty different front chassis clip and engine set back. My mistake was thinking, heck if a 454 fit, anything will fit... wrong.. 

I've since installed new inner fender liners. Just so much easier to work inside this thing with them out!

Sorry if my post is in the wrong section. New to the site wasn't sure where this should go. Just wanted to help any others that were contemplating this type of swap as I've read around without much luck on what works and what doesn't.

[bake74]

      Gen3, I tried to respond to your pm, but your inbox is full.  Until you post so many post on this site you only get a few.  Delete some so I can respond.

[Captkaos]

You are better off going with the 80E, if you plan to use that turbo it is just a matter of time before something breaks on that 60. 
Being a 73-87, the LS Factory AC mount won't work on our trucks without some forethough and money, it can be made to work, but it is easier in my opinion to move it up high.  The problem with your setup is the Turbo is where most kits put it.