1990 GMC RCSB Turbo LS Swap

[Thunderwagen]

I have been slowly cranking away on this thing and have finally made a little progress. A little back story on the truck is I purchased it from my father inlaw back in 01 and drove the hell out of it until 2007 when the 700R4 finally gave it up at 243K. Since then It has sat while I collected parts and figured out what I wanted to do with it. The plans have slowly snowballed from being just a nice driver to something a little more.

I started out stripping the TBI 5.7 and 700R4 out and completely pulled the front suspension out of it to clean up the frame and get it painted. I ended up using DJM tubular uppers, DJM 2" dropped spindles, 2" Hotchkis drop springs, all new Moog ball joints and steering components, AGR 12:1 steering box, PST poly bushings, and Hotchkis sway bar. The rear suspension that I haven't gotten to yet is going to be a 6" flip kit with Caltracs on a 9.5 14 bolt I got out of a 454SS. I will see how far I can get with this set up before I end up 4 linking it to get more tire under it.

For the motor and trans I am using the 9.5:1 370 with AFR 225cc heads and built 4L80 out of my VHO with a T6 Borg Warner S400 80/87, Precision 66mm WG, Tial 50mm BOV, Holley High Ram, FAST 102mm TB, FIC 127# injectors, Circle D 3200-3400 stall.

I just dropped the truck off at Trick Performance and he is going to be building my hot parts. Im going with a T6 log and 4" down pipe. He is also going to use my truck to come out with a bolt on kit for the LS swapped OBS trucks. He is going to be offering kits to fit with high mount A/C and without A/C. Im sure either myself or Rick will be updating with progress pics as he gets it cranked out.

Here are a few pics of where I started and where I have gotten so far. Im sure it is going to take me a while to get this thing finished but it is coming along.

[Thunderwagen]

A few more pictures

[mattcrp1]

Nice manifold.

[69trk]

watching

[memphismatt]

Cool build looking forward to seeing this come together

[Thunderwagen]

Rick sent me a picture of a T4 bolted up with the new A/C brackets so here you go.

[jb1016]

subbed on this one for sure, looks like a great project.

[fluffyfreak]

Nice im in

[Zane M]

Looking forward to this progressing.

[Greenlee]

Nice work!

[Chris95GT]

Nice. That looks like the same Magnum T76 I have for my 91 with a 5.3. Any more info on when he'll have hotside kits out for OBS trucks?

[Thunderwagen]

He said you could order it now and he will have it ready to go in 4 weeks.

Here is my T6 mounted up

[Chris95GT]

Which AC brackets are you using with this soon to be kit? I was going to go with the ones here from lsbrackets.com

[Thunderwagen]

They aren't out on the market yet. Trick had lsbrackets custom cut them. The other ones wouldn't work with the turbo manifold without modifying them so he got with lsbrackets and they came up with the ones in the pictures.

[61_FL_Apache]

Watching this one take off!!

[Thunderwagen]

I talked to Rick and he said he should have the T4 kit wrapped up next week. He is just waiting on the intercooler to come in.

[69trk]

do you have a picture behind the turbo so i can see how the manifold lays out? i have a sanden compressor, just seeing if this will clear...

[Thunderwagen]

If its for your c10 I would talk to him about taking your truck to him. I know he's looking for a 67-72 with an ls swap to build a kit off of.

I will ask him to send me some pictures of the T4 kit he is doing on my truck though.

[smoky02]

**** I can send him my truck right now...lol...

[Thunderwagen]

Here is a picture with the 3" down pipe on the T4 kit.

Also the ac brackets are now available through lsbrackets.com

[SCOTI]

Subscribed.....

[Blitz]

VERY interested to see where this goes. I might have one to send over if it's a success.

[kpc01]

Originally Posted by Thunderwagen

If its for your c10 I would talk to him about taking your truck to him. I know he's looking for a 67-72 with an ls swap to build a kit off of.

I will ask him to send me some pictures of the T4 kit he is doing on my truck though.

I will have to talk to him when I get to this point as well. doing an LS motor (and hopefully the same turbo setup as you) in a 64 C10...

[tinydb84]

I have a love hate relationship with this body style. Most of the time I don't like them but when done right I start looking on craigslist for another project I don't need. Man that thing is going to haul ass!

[Thunderwagen]

Just to update this a little. I got the truck back from Trick several months ago because I found out he was coming out with a cast T6 manifold that completely divides the banks inside the passengers side log. This will help tuning wise since it will keep the banks separate for the O2s. He just got the first shipment in last week so I should have mine in hand here pretty quick and I can finish out the hot side of the turbo setup.

I really haven't done much of anything other than tear the front clip back off to pull the motor so I can detail it and get the covers powder coated. Other than that I have been collecting parts.

I got new cross drilled and slotted rotors for the front and had them redrilled to 5x4.5 and turned down so they would be hub centric to the new wheels I got for it. They are 20x8.5 and 20x10 and I got 245/40/20 and 295/40/20 Falkens for them. These wheels are just gonna be the street wheels and I will get some skinnies and slicks for when I really want to play. On the back I have gathered up stuff to do a disc brake conversion on the 14 bolt. I am using impala rotors, speedway weld on caliper brackets, 69-77 gm mid size calipers and the lines and fittings to get it all to work.

The holidays and what not kind of slowed me down a little. Im hoping to bang out the rear suspension here pretty quick and install the fuel cell so I can put the bed back on. Then once the motor and trans are in for the last time start saving for all the Holley Dominator crap Im going to need, and finish up the cold side of the turbo setup.

I will get some more pictures up once stuff comes together.