build ???
Unless you're planning a big budget all-out build...

So many directions you can go here. What's your budget? (that will probably make decisions for you). There is a big difference between what you want and what you need. You asked what "the best" parts would be - well, I'd say Callies Racemaster or Magnum are two really nice cranks; I think those few who are running the mystical lightweight COLA crankshaft are to be looked up to... I would have LOVED to have received a set of Oliver billet rods for Christmas a few years back... there are plenty of good pistons out there (I'll mention JE). The above mentioned parts would represent a really nice forged rotating assembly. Then again, you can spend half as much (maybe even 1/3 the cost!) and get a forged Eagle rotating kit that would be strong as hell.
We haven't even started talking cylinder heads yet... I think budget will answer most your questions. One important Q would be what do you want to do with this engine/car? (daily driver? emissions yes/no?, race car project? etc).
AI has a good priced rotating assembly.but a local machine shop would have to machine the block. and if your new to it. theyd have to build it up for you aswell.. and that can become Very costly, as opposed to heads and a bigger cam. You already have LT4 heads. theirs alot to get out of them
For example, when I did my build, I wanted a low 11 second car that would look decent, that I could drive 50 miles to the track and back, and still drive 200 mile round trips if I wanted to in summer heat.
Trending Topics
good luck with the build and keep searching theres alot of decent info out there
The Best V8 Stories One Small Block at Time
Considering what you have (if correct) above, I'd imagine you wouldn't be tearning out and apart that motor to simply build up a 450+ crank hp 383, right? You could slap a blower on your current engine and be making 450 hp at the wheels.
So you'd want to consider a good forged stroker kit - I think for $1500 or so you can get a very decent 4340 Eagle crank & rods and a good set of forged pistons. Do you want to spend another $500-$1000 to beef up your block? - that's something you might want to consider... If you're really holding on to LT4 cylinder heads you "could" keep them as is and go for a custom low revving torque monster cam shaft (or even a proven off the shelf cam). Or you could consider spending the $1000-$1500+ on a serious heads&cam package that would make that 383 into a high reving screamer (like 6000-6500RPM peak)... in this case start to think about beefing up the block.
There's so many other engine parts you'll need to consider replacing. And assume that a good number of stock parts will have to be replaced anyways. I ended up replaced EVERYTHING with my 383 build. The only original parts from my old 355 LT1 on my new engine are:
1: the waterpump housing (although I did the electric pump converstion
2: my stock fuel rail (polished rails and painted red crossover tubes to match LT4 intake)
Thats it! Every single other part, sensor, bolt & screw had to be new. You don't have to go this nuts but one part you may want to consider replacing - or at least prepared to possibly replace - would be the optispark. I sprang for an MSD billet opti. The LSx coil per plug conversion is another option but pricey. The MSD opti goes for $500.
Oh geeze, if we're talking cam swap you really should consider replacing the entire valvetrain - you'll be forced to change the springs no matter what; if you in fact have the GM 1.6 roller rockers already you could use those but recommend you buy brand new chromemoly pushrods and new lifters.
the **** adds up quick.

