Small Block & Big Block Chevy Specific - chevy 383 questions

rules:

1. I am on a serious budget and cant afford alot.
2. I cant afford a kit, it has to bee done a little at a time.
3. I have a 350 with a bad crank and a bad rod.
4. I have a 400 complete bottom end but the block is cracked.
5. im not looking for performance, just a decent running motor

Questions:

1. If I use everything thats in the 400 does it still need to be balanced?

2. Do I need special pistons or just .30 over stock ones?
(remember I'm using the stock short 400 rods not the 5.7 rods)

3. Is the stock 350 cam fine or do I need a new one?

4. Is the stock throttle body good enough?

You can use the 400 crank and rods in the 350 block. It will have to be machined for clearence. You dont have to use special pistions but if you bore it out you will have to get new ones. As far as the other questions what do you want out of the motor? you can use the stock cam and throttle body but you wont get the most out of the motor. whats it going into? on a side note i spent about 650 dollars on rotating assembly. which is pretty cheap i think that included forged pistons on stock rods and 400 crank.

If you are going to use new pistons anyway, use the long 350 rods. Also change the cam while you are in there.

I don't think if you use the 400 crank and rods, you will actually have a 383 will you?
I would use the 5.7 rods and bore it 30 over. Get the right pistons for that setup. Notch the cylinder skirts to clear the connecting rods, and run it. That is the best engine GM never built.
With a 400 crank, I am pretty sure it is still externally balanced, unless you pay to have it balanced. That will cost coin.

You don't have to change the cam if you don't want to. But like what was posted earlier, you won't get all out of it that you could.

in order to get that crank to work in your 350 motor you're gonna have to go through alot mroe trouble than its worth. first problem 400 mains are larger than the ones in your 350, so ya gotta turn em down to proper 350 size. also in order to use a standard 350 piston when you have 400 the rods resized you'll have to have them made shorter to keep from coming out of the deck quite a ways, then the other problem is getting the piston skirts to clear the crank counterwieghts. it is a workable situation guys did it years and years ago but nothing about the labor involved was cheap. my suggestion to you is just to buy another 350 crank and a set of budget or rebuilt rods from whatever shop you use for machine work and reuse your old 350 pistons after cleaning and some new rings if your budget is really that tight. then again with a bit of looking... you can get a balanced eagle rotating assembly for a 350 chevy for about 5 bills with bearing and rings, 7ish for a stroker.

The 400 crank has larger main journals. You'll need new pistons, bearings and a balance job.... it's not worth the money because you can buy a complete balanced set for not much more. The cheapest vendors are Powerhouse and PAW, see magazines (SuperChevy for example) or search the web.

The stock cam is not going to bleed a lot of compression off, shoot for 9:1 comp ratio with a stock cam (advertized piston CR)... if you choose a cam in the 225/230 degree range (advertized at .050 lift) then bump the CR to 9.8:1 or so....

with your stock cam you'll have a torque monster, lots of low end power - good for a truck...

I found that it's as cheap to just buy an assemble short block. If you pay for cleaning, magnafluxing and machining your block you look at around $500-$600, a rotating assembly is $500... the assembled short block is $1200 (PAW, Powerhouse).... not much more but in includes bearings and assembly...

I don't think if you use the 400 crank and rods, you will actually have a 383 will you?
I would use the 5.7 rods and bore it 30 over. Get the right pistons for that setup. Notch the cylinder skirts to clear the connecting rods, and run it. That is the best engine GM never built.
With a 400 crank, I am pretty sure it is still externally balanced, unless you pay to have it balanced. That will cost coin.

You don't have to change the cam if you don't want to. But like what was posted earlier, you won't get all out of it that you could.

yep, externally balanced. when i turned my 350 TPI into a carbed 383 beast, i help to buy a new balancer and flexplate. then i took it to a shop to make sure it was balanced good for what i wanted to do with it.