No truck should be that unreliable. Although Dodge and Jeep seem to have more than their share of problems.
Some CHEVY/ GMC ( same truck different badges) has good years and bad years. Same with FORD.
CHEVY 1995-1999 tend to be good ( mine went 371,000 miles 20 years with only $1000 worth of repairs. Rust ate it up.( I’m in the rust belt where a snow fall requires thousands of tons of salt). Untouched engine/transmission right up to dropping it at the scrap yard. I built my 5500 square ft house hauling all the Timbers and granite stone sometime carrying over 5000 pounds in the bed or pulling 20,000 pounds on the trailer.




Ford, avoid the modular engine. It tends to spit out spark plugs or the spark plugs break apart and drop in the cylinders. When Ford went to the 5.0 liter all aluminum engine and 6 speed transmission it’s really spectacular for power, fuel economy, ( average 22mpg ) and durability. That started in 2005. Mine with 9 years driving in heavy salt there isn’t a single spot of rust anyplace. It’s so awesome you can’t believe it’s been used. ( but wear on the seat really proves it has.).
Avoid The later 8 speed & 10 speed , they had problems although I understand that’s not the issue now. It’s just lately quality control is in the toilet.

 

I'm probably being too harsh on the old girl, 330 thousand miles had to take it's toll eventually.. just recently finished building a transmission that uses almost none of the original chrysler junk. Torque converters have been the real issue though, can't buy them new and I haven't been able to get more than a couple hundred miles out of the rebuilt units :/

at least rust is barely a concern around here, we use sand instead of salt here so things usually last until mechanical failure.. which is good cause newer trucks are far too large for my taste

 

New trucks are giant sized. I’ve always owned regular cab and a short box (6&1/2’) they fit in my garage. But those crew cabs even with the 5&1/3’ bed won’t.
I’d actually prefer the next size down but they get worse gas mileage and don’t tolerate the heavy hauling I often do.

 

Regarding the manifold. I can see buying some pre-bent aluminum tubing and making your own plenums using a Chevy throttle body on each side.
If you go to a central plenum air distribution tends to get messy. Plus then you are more or less forced to use 1 single big turbo. Which handicaps you at low rpm.
Use Two smaller turbo’s on either side, go through the engine compartment side panels with a tube and stick the turbos behind and above the front wheels.inside the front fenders
Turns the car into a real sleeper. Plus makes tubing so much shorter and easier to deal with.
You’ll probably hate this, but don’t use “headers”. The stock cast iron ones work really well because of the firing order on a V12 works while a V8 or 4 cylinder forces adjacent cylinders to fire in an uneven sequence.
My race headers took 27 feet of tubing, effectively blocking all the air flowing through the engine compartment, causing a real heat problem.
I later found out that at most the add 3% more power at the cost of a whole summer spent cutting and fitting things together only to find something in the way. Forcing me to start over again either a different plan of attack
Commercially sold tubular exhaust manifolds don’t add any more power. ( nor do they make that claim)
if you want to see the way to build headers Go on U tube and watch Robert Knodt’s Camp Chaos he’s got a whole series on that.
by the way he races a Jaguar XJSV12 and he really does great videos.

 

For a central plenum with twin turbos I was thinking about doing something like this:

would hopefully make use of the space left by smog pump and p/s, alternator might need to be moved... somewhere
I don't intend on copying the blow off pipes through the hood though that's for sure, I'm not sure if you can call a build that started out as a sports car a sleeper but I do want to avoid mutilating the bodywork where possible, although some fender mods might be in order to squeeze in a little more tire
as far as headers go I think they're silly on a turbo car anyway, they're worth it on NA cars just for the sound though... I was thinking about doing essentially just a large pipe with a flange for each exhaust port and the pipe mounts directly to the turbo.. not sure if that's ideal for flow but it certainly is simple

pretty much like this.. almost seems too simple to work well though

 

I should have taken pictures of my twin turbo set up. Sorry I didn’t.
Here’s what I found out though. Back pressure kills the engine almost as much as heat does.
Forcing air though a intercooler, adds a lot of back pressure. (How much depends on several factors such as size, inlet & exhaust tubing size, bends & curves. Involved etc. the best intercoolers tend to be the big bus sized ones. But those block the radiator from doing a good job of keeping the coolant temp down.
Don’t fall in love with any one number if you want things to last. I hate to say it but moderation is really the key. Almost never will the very last bit of power/boost/ or anything. Be the end all. I vintage raced with the same engine untouched ( other than regular maintenance) for over 20 years. The car got faster and faster over time due to me learning the tiny little things it takes to be good.
Those who built hand grenades wound up spending so much time and money working on it they became discouraged and never did learn the little things.
Personally welding up a manifold doesn’t gain enough to offset the time invested. that’s hours worth of work with risk of failure the way you are suggesting.
You don’t want a really big turbo. It takes too long to spool up so it will feel sluggish. Two smaller ones spin up much faster. And peak power is very close. Plus then it’s really easy work to go to a bigger pair of bigger throttle bodies.
Besides peak power typically doesn’t get used much other than on the dyno. ( primarily for bragging purposes. And never on the street.
Even if you have a long empty road, it’s hard to use the full power of a well tuned twin turbo engine.
Only on big long tracks like ELKHART LAKE ( a 4 mile track) there are only 3 spots where if you have the exact right gearing you can reach full potential. And there, someone even momentarily blocking you, you won’t achieve it there. Nor if you take a slightly off line exit.
I used to use a fractionally taller gear ratio so that if another fast car was ahead I could tuck into his draft and use the tiny bit left to pull ahead and pass.
Winning is a mental chess game. Where things like that make the difference.
I digress. Use a pair of stock intake manifolds ( with bigger throttle bodies
from the throttle body go forward through the inner fender, 90 degree bend to the rear and straight into the turbo.
The stock exhaust manifolds join together and then goes up underneath the inner fender and into the Turbo.
Such a short length from the turbo to the throttle body will ensure it doesn’t pick up any engine bay heat. With only 1 bend in the system. Back pressure is at an absolute minimum.
As will be heat pickup and the heat gain from the turbo will be easily dealt with by the alcohol in E85.