Hey guys. I have a 86 TA and ive been planning a twin turbo jy project for a while now, and I recently aquired a 400SBC and a th400 trans out of a mid-80's heavy half ton van. Im wondering what might be a good combination for turbos for such a setup. It will be intercooled, and water/meth injected. I also plan on running 8-8.5 compression so i can run a bit more boost and timing. I plan on getting a custom cam ground. I know its a pretty vague post, but i'm toying with different ideas before i start buying parts. Also, im also getting a TPI setup and was considering a MegaSquirt.

turbo size? it depends....race or street or both? How much you want to spend? If you want JY turbos I think you will be looking for diesel turbos for a dual setup. You could go Ford T3's but I would go with diesel twins.
Putting a TPI on that 400SBC is a big mismatch. Starting to buy parts? I would figure out & buy the turbos first. Buy everything else around that. Having the turbos sitting around will also give you motivation to actual build it.

GM was making 400SBCs in the 80's? What year is the 400 block?
What is the budget for the complete Twin Turbo 400SBC? Sounds like you are tearing it down. What do you figure........about $5000 for the engine, turbo&parts, and intercooler?

i checked out the year, the van is a 1980, they stopped putting in 400sbc's in 1981. The car is going to be mostly street and some road race stuf. not much drag racing around here as the closest track is like over 2 hours away. Budget isnt really set as of yet, im plannin on 2-3 years before i have the car the way i want it, right now im in the process of strippin it down to the bare shell, so i can get it dipped and then go through and weld all the seams up. its hard to say how much money i can spend on my car, as im building a 65 chevy truck for my fiance at the same time.

if you are going more for a road course type project DO NOT use the 400 and DO NOT use junkyard turbos. its my opinion that you can find good aftermarket turbos if you look in the right places, for about the same as a rebuilt junkyard one. and the aftermarket ones will perform better as well.

as for the 400, if yous tay NA it would be ok but boost and big cubes makes lots of low end torque which could be dangerous with a road course car. you want something thats not gonna have 600+ft lbs at 3k rpms as you will be pulling yourself off the wall.

sell the 400 to someone wanting a drag only car and buy yourself a 350 with the money. i would bore it .030 over to clean it up but keep a smaller engine.

the common saying on this site is "theres no replacement for displacement." well if you live in the real world where cars turn at the end of the straight away, the replacement for displacement is boost. and boost and displacement might make huge numbers but good luck putting it down.

I agree with what you said about the JY turbos & 400sbc. For beginners, it is very hard to find the "right places" for aftermarket turbos. If they are external wastegate then it is no comparison. One good aftermarket external wastegate costs more than two internal wastegate JY turbos. But yeah, if you have a little extra to spend then new turbos would be better.
Street/road race, I would go with the 350 or 327. 350ci is the best value vs. dollar.

i agree with that. but with a turbo setup you need to spend the money right the first time. if not you are going to be spending a lot more money later.

Well, I've been reconsidering my usage of the car, and i guess road racing really isnt going to happen. I really never checked around the area until now, and there is nothing even remotely close as far as a road course. So, its drag racing or nothing, and even the closest drag strip is almost 3 hours away. I guess the car is going to be used for cruising around the country side looking for parts for my other project vehicles. I have a couple 350's laying around, i think i'll do the turbo setup on one of them, and put the 400 into my fiances truck that i'm building.(65 chevy 3/4 ton). Thanks a bunch guys.