My intro
Thread Starter
Teching In
Joined: May 2019
Posts: 11
Likes: 0
My intro Hi everyone.
I'm joining because a thread about Ferrera stainless valves led me here. I've bounced around but now that I actually have a LSx platform I figured I should join.
I have a 1986 C20 Squarebody. 305 with a SM465 transmission. I get 9.5 mpg on the highway.
It was a work truck. I'm not modding it.
So naturally I was going to swap a 5.3. I bought a junkyard 5.3, wired the harness, replaced all the gaskets (sans HG), and got it ready to drop in. I found a 2wd NV4500 and I rebuilt that too...
But somehow it spiraled into a GMT800 4wd frame swap, the 5.3 was replaced with a 6.0, and the NV4500 was disassembled to receive a 4wd mainshaft, and I bought a NP261 transfer case.
Now I have a disassembled 6.0 with 317 heads. I'm going to shave .025-.030 off the heads and I'm replacing the pistons with flat top LQ9 pistons trying to get to 10.0:1 compression. I'm planning on a mild bump stick and hopefully 400 N/A HP.
Pistons will be OEM LQ9 replacements. Head studs will be Chinese imitation ARP, ARP rod bolts, eBay long tube headers, truck intake manifold, probably a 92mm throttle body.
I'm planning on some stainless 2.0/1.55 valves, PAC1218 springs, and I haven't priced out pushrods yet.
Hoping to see 16mpg city and 21 highway.
Might seem like overkill and under powered but I carry motorcycles across the country to events and haul manure for gardens. It's still a work truck.
I'm joining because a thread about Ferrera stainless valves led me here. I've bounced around but now that I actually have a LSx platform I figured I should join.
I have a 1986 C20 Squarebody. 305 with a SM465 transmission. I get 9.5 mpg on the highway.
It was a work truck. I'm not modding it.
So naturally I was going to swap a 5.3. I bought a junkyard 5.3, wired the harness, replaced all the gaskets (sans HG), and got it ready to drop in. I found a 2wd NV4500 and I rebuilt that too...
But somehow it spiraled into a GMT800 4wd frame swap, the 5.3 was replaced with a 6.0, and the NV4500 was disassembled to receive a 4wd mainshaft, and I bought a NP261 transfer case.
Now I have a disassembled 6.0 with 317 heads. I'm going to shave .025-.030 off the heads and I'm replacing the pistons with flat top LQ9 pistons trying to get to 10.0:1 compression. I'm planning on a mild bump stick and hopefully 400 N/A HP.
Pistons will be OEM LQ9 replacements. Head studs will be Chinese imitation ARP, ARP rod bolts, eBay long tube headers, truck intake manifold, probably a 92mm throttle body.
I'm planning on some stainless 2.0/1.55 valves, PAC1218 springs, and I haven't priced out pushrods yet.
Hoping to see 16mpg city and 21 highway.
Might seem like overkill and under powered but I carry motorcycles across the country to events and haul manure for gardens. It's still a work truck.
Welcome to LS1Tech! Sounds like your project snowballed because just like me and most others, you said to yourself “while I’m at it” and you came across a “deal to good to pass up”. We’ve all been there. I just finished an 87’ last summer that my brother bought when new. It has 54k original miles. He special ordered the truck midnight blue, 350, 4 speed, g80 rear, a/c, stepside bed, and appearance package front end. It’s his baby. Frame off build, with 17” lift, 44” bloggers, custom built 20” wide bead lock wheels, 10 shocks under it, bla, bla, bla. Original 350 block however. He wasn’t engine swapping this one. Love those square bodies.
Thread Starter
Teching In
Joined: May 2019
Posts: 11
Likes: 0
Nailed it, Che70velle.
I love the truck. It reminds me of my childhood. From the smell to the manual crank windows.
Some things made sense. Some things didn't.
Swapping an engine that triples the HP and doubles the fuel economy while not requiring me to adjust the jets every 6 months makes sense.
I would need a specific model 87 gas tank to use an electric fuel pump, which means a new tank, sending unit, fuel lines...
I wanted 4 wheel disk brakes but, being a manual, I needed to keep the e-brake. There are adapters using El Dorado calipers but then I found the GMT800 frame for 200 dollars. Because I live in New England I had already made the decision to convert from 2wd to 4wd. I bought an 85 4wd long bed frame for 400 dollars in Pennsylvania and then the GMT800 frame came up less than an hour from me for 200 dollars.
I get contemporary suspension geometry, 4 wheel disk brakes, plastic gas tank, sending unit, all while keeping the 8 lug 3/4 ton axles. And a hydroformed fully boxed front frame. To me it's like sacrificing nothing and gaining everything.
The downside is that it's about 4 inches wider so I need to move the bolts that hold the bed to the frame out 2 inches each, fabricate cab mounts, and I had to cut 2 inches out of the frame (87 is 131.5" wheel base, 06 is 133.5"). I cut it at the weld between the front and rear frame sections but I haven't glued it back together yet. I'll need a drive shaft that is 2 inches shorter but that means the engine, trans, xfer case, and front axle can all be OEM, stock bolt ins.
I love the truck. It reminds me of my childhood. From the smell to the manual crank windows.
Some things made sense. Some things didn't.
Swapping an engine that triples the HP and doubles the fuel economy while not requiring me to adjust the jets every 6 months makes sense.
I would need a specific model 87 gas tank to use an electric fuel pump, which means a new tank, sending unit, fuel lines...
I wanted 4 wheel disk brakes but, being a manual, I needed to keep the e-brake. There are adapters using El Dorado calipers but then I found the GMT800 frame for 200 dollars. Because I live in New England I had already made the decision to convert from 2wd to 4wd. I bought an 85 4wd long bed frame for 400 dollars in Pennsylvania and then the GMT800 frame came up less than an hour from me for 200 dollars.
I get contemporary suspension geometry, 4 wheel disk brakes, plastic gas tank, sending unit, all while keeping the 8 lug 3/4 ton axles. And a hydroformed fully boxed front frame. To me it's like sacrificing nothing and gaining everything.
The downside is that it's about 4 inches wider so I need to move the bolts that hold the bed to the frame out 2 inches each, fabricate cab mounts, and I had to cut 2 inches out of the frame (87 is 131.5" wheel base, 06 is 133.5"). I cut it at the weld between the front and rear frame sections but I haven't glued it back together yet. I'll need a drive shaft that is 2 inches shorter but that means the engine, trans, xfer case, and front axle can all be OEM, stock bolt ins.
