I want to go turbo no doubt. I think I found a good deal on a 400 block ready to be assembled for a 377 and some h-beam rods for a good price. however would this work well with a bigger turbo t-73 or t-76? i guess i could always go with a bigger turbo if needed. i plan on running afr heads but if anyone could help that would be great!

 

Both will work, you most likely will see very little difference in the overall power. It's not so much the compressor but the exhaust housing. Find out what housing is on them. The smaller the housing the faster the spool which would deliver stronger low to mid range flow, but will hinder top end power. Example .60/.63 a/r housing. Going with a larger would take more time to reach max speed(lag) however it would produce a higher rpm operating range of the motor. Example .83/.96.

It all depends on what you plan on using the motor for. Running on the salt flats with a 377 and a T-76 with a .96 a/r would be a top end monster. For the street You may want to look into a slightly small er housing and use a decent stall to get the turbo to spool.

 

Well it definitely is going to be street able. That's one of the main reasons I am building it. I am not sure yet what I am going to spin my motor to. I talk to a fewpeople who got 7500. I may go to 7000. What would you recommend for that? I want something that is able to drive on the street yet go to the track and throw some sinle digit number down!

James

 

It's gonna cost you a fortune just for the valvetrain to attain that rpm. Even then running it at those speeds you will go through valvetrain evry year or so. Seems like all race to me. If you got a lead on a 400 block i would purchase the gm crank from their 383 crate motor(3.80). It is a forged piece made from 4130 i believe.

Next I would look into a set of 6in. rods. Again forged, there is a lot of force applied to the rods once you start running some serious boost. Lastly pistons again forged why skimp on a part that can make or break your engine.

Now with that combo(not having to spin it to 7000, although you could) would save the valvetrain, make very good low and midrange tourqe(street manners) and you could use a smaller turbo that won't kill your drivability by having to go to a 3500+ stall converter. Something around a 70/72 with a .68 housing will spool very well, make a lot of mid range power and get you some very good track times.

Single digits and streetable usually don't go together in the same sentence. Set up right you could have a low 10 sec. car that would be mild mannered enough for the street. You also have to take into account an IC and once you start running 25+ psi; race gas. Also what intake will be on it what tranny(that much power prolly a th400 which means your gas mileage will be down). If you want OD you'll have to use a gear vendors or a 4l80E which the last time I checked were a fortune just for a stocker and it still needs a lot work to stand up to abuse.

 

Well originally I wasn't planning on doing a 377. However I ran across a VERY good deal. I bought a 400 block freshly bored with no miles for $200. I bought NEW Eagle H-beam rods for $200. They are 5.7 inch for a 377. I found a crank I will probably buy next week that is 4340 forged. It's a eagle SCAT crank. guaranteed up to 900 HP for $400 New. Then I am going to get my pistons later on. Since I am still doing work onthe chassis I am not concerned on buyin parts unless I see a deal. I doubt I willl spin it that high. I was just throwing out ideas.

I have a TH400. I am going to do my best for single digits and streetability simpy because it isn't seen often. I have a friend wit a 393 and a t-83 turbo that is street able and I am getting to help me with little stuff. The only time I will run high boos would be againsta big competitor........so it would be low boost most of the time. I plan on having the complete kit assembled by a guy locally that builds turbo kits for people.

James

 

Does the crank have the large journal of the 400 block? If not you'll need bearing spacers. Same as the 3.80 crank. However you will be able to use a 350 balancer and flywheel/flexplate with the 3.80 crank. I'm sure the pistons are costing you a pretty penny. It's doable, but it'll prolly cost ya. depends on what you consider streetable though. I know in TX, you can get away with a lot more than other places. I was there for 2 years and ran my iroc with straight pipes, they just don't care down there...

 

The rednecks don't care what is on your car as long as it looks and sounds good. Streetable-Able to drive it whenever/whereever....The pistons will probably cost $400 + if I get them new. Usually I find someone that has no use forthem just like the h-beam rods. I am going to use bearing spacers with a 350 crank.