LSx in an 86 C10, what turbo manifolds??

I'm looking at buying a 1986 Chevrolet C10 and would like to put together a 370 cube 6.0 and a set of twins. Maybe some PT 5557 billet BB turbos. I have some C6 manifolds and truck manifolds. Which of those can I use or does someone like Stainless Works make tubular headers to put a turbo LSx engine in this chassis? Keeping all my accessories is a must. With a goal of 600-700 whp should I build the TH350 currently in it or look into getting something else for it? I'll put a 2.73 or 3.08 gear in the rear and run a 29" or 30" OD tire on the back

Anyone?

Since u have both sets of manifolds, try them out and see which pair works best, I'd guess the truck manifolds would.
We have the flanges you'll need to connect the hotpipes to manifold mount surface.

I'd build the th350, since it's inexpensive and u have it.

The gears sound just fine for the application. I had 28" and 3.08's before this setup.

I think I'd rather have a tubular manifold just for sheer aesthetics. On a 370 with 9.5 or 10-1 compression running 93 octane with a goal of 600-700whp should I do a mid 70mm single or a pair of the 5557s I was talking about? I know you have a lot of experience with turbocharging this engine so I wanted your input. Cam will probably be a mid 220ish and the heads with either be worked factory castings or AFR 225s and a TBSS intake manifold with a 90mm throttle body

Nothing wrong with having tubular manifolds.
If you're looking for 700whp, build the engine with 10:1 and use a pair of 68mm turbos, with .68 a/r housings. If you're doing a single, an 80mm would be just right.
These two suggestions will make over 700hp with supporting mods, but I'm considering the higher compression 6.0L.
They will spool up just fine and have room for future upgrades.

The owner can chime in if he wants, but one of the best stroker engines (408) I've had experience with was a 10.6:1 408 we built.
It had great NA power, boost came in just fine, almost too fast with .68's, and easily made over 830hp on low boost, on pump gas.
With more pressure and race gas, I bet it would be a 1000whp engine.

I built a 408 a little while back for a Camaro I had. The compression was 8.8-1 with a 236/236 .617 lift on a 114lsa. I was planning on running a single Precision 88mm turbo with a .96 housing. That was going in a 98 Camaro SS with a goal of 1k whp. I am weighing options now for this build

I think 8.8 is a little low on the compression. It'd be a turd off boost.

The compression was so low because the boost was going to be very high. Wouldn't running a 370 vs a 408 help soften the low end torque so the truck would stand a better chance of hooking?

My truck has 8.6cr, I plan to run high boost one day as well. Making a few changes, then I'll crank it up where it needs to be. The truck felt fine under NA driving as well, when I used to drive it on the street; of course it's not real heavy.

I think both of those engines will make good power regardless. Get tires or suspension for hooking, don't let traction determine which engine to get.
There's probably no difference between those two engines when they are being forced fed air.

We'll see I guess. I've wanted a nasty turbo LSx for a while now but every time I try and do it something comes up. I had a friend of mine telling me about those Precision 5557s and running them on a 370 for my Camaro. I think instead of turbocharging it I will get one of the AES 390s and do either a D1SC or F1 and shoot for 850whp. Putting a pair of turbos under the hook of a 4th Gen really is like putting 15lbs of shit in a zip lock bag. If I go twins it will be 370 with either 5557 or 6262. If I go single I'll look seriously at going 402 or 408 and get a 76 or so. I think an 88 like I had planned for my Camaro will be too big and have too much room for growth. I'd like to be in boost by 2500 and shift at 6200-6700. Plus spooling so low I wouldn't have to run an ignorant TC and should be a great driver

Since you haven't built the trans yet I think you should consider a 400. Do it once...

I think if I were to do a tranny swap I would get a 4L80. The swap wouldn't be much different and I'd get a 4th gear and OD