You have a lot to gain by stroking a 350 to a 383. That's 33 more cubes which means a substantial increase in horsepower and torque over a comparably built 350, usually at lower RPMs too.

There are several connecting rod styles you can use in a 383 from 5.565" to 5.7" to 6" and many, many piston configurations to suit your needs and your selected parts. That's where you have to set a realistic goal of what you want with a realistic budget. Then determine the correct parts that will work together to achieve your goal. If you're starting out then it's going to take a lot of learning. Don't just take what you read on the internet and in message boards, go out and get yourself some good basic engine and hotrodding books and start reading.

 

OK i have a question about putting a 383 crank in a 350 block.
what rods do you use and what piston?
i have people telling me that if i put the crank in i have to use the 6" rod but use diff. pistons but i if do that it will put the compression back where i started and did not gane anything.

so i guess my question is what are the advantages of putting a 383 crank in a 350 and what rods and pistons do you run

thanks guys

It's actually a SBC 400 crank in a SBC 350 block that makes a SBC 383.

 

It's actually a SBC 400 crank in a SBC 350 block that makes a SBC 383.

Isn't the 350 block .30 over to?

 

All of the above... There's no such thing as a "383" crank. A 383 is, as the others have pointed out, a 350 with a 400 crank and bored out to .030" over. You can use either 6" or 5.7" rods, depending on which pistons you want to use and whatever is in your bottom end kit, if you get one.

Your final compression ratio depends on your piston dome and what you're doing with everything. Just because you use a 6" piston vs. a 5.7" one doesn't mean squat about what your CR will be. You can pick just about any piston/rod combo you want to get the CR that you want...

You can try to piece one together, but I'd just get a whole rotating assembly from somebody like eagle or scat. They've done all the engineering and guesswork for you, just buy the kit and be done with it.

 

There's no such thing as a "383" crank.

That's not entirely true anymore. Aftermarket 383 cranks are widely available. They are specifically designed to be used as 383 cranks as opposed to modifying a 400 crank to fit.

 

Isn't the 350 block .30 over to?

Yeap it is

 

The stroker cranks typically come in two types; those that are designed for 5.7" rods and those that are designed for 6" rods. The difference is with counterweight mass. A crank designed for 6" rods really needs 6" rods. A 5.7" crank can use either rod, but using a 6" rod means a good bit more money in balancing on the 5.7" crank.

The benefit to using a 5.7"-style crank with 6" rods is that it can usually be internally balanced.

 

That's not entirely true anymore. Aftermarket 383 cranks are widely available. They are specifically designed to be used as 383 cranks as opposed to modifying a 400 crank to fit.

Very true. I guess I was just referring to the 400 crank for historical purposes!

 

For a little more historical back ground the first 383 used the 5.56 rods from the 400 too. Because regular 350 pistons and 5.7 rods would pop out the hole. But now you can find 383 pistons with the pin moved closer to the top everywhere

 

i just made a chevy 383 and i love it :thumbup: im thinking of making another one these time i want to put a single turbo chevy all the way :thumbup:

 

The GM 383 crate motors like the HT383 are 4.000" bores with a 3.800" stroke so I guess that would be a "true" Chevy 383 crank. Wonder what piston availibilty will be when it comes time to bore one of those out?

I built a 383 in 1982 with the short 400 rods, 441 heads, cast pistons with no wuench, single plane intake, single pattern cam and mechanical dual point. We thought it was a killer, according to DD2000 it was a relative roach and it's 1/4 mile times confirm the DD results. I'd love to build another one the "right way", I've got the SCAT crank, eagle rods and NIB L-31 Vortec heads. Maybe the time is near......

 

f all the bull just go for it make that 383 they are lots of fun :thumbup: f those jap cars up

 

The GM 383 crate motors like the HT383 are 4.000" bores with a 3.800" stroke so I guess that would be a "true" Chevy 383 crank. Wonder what piston availibilty will be when it comes time to bore one of those out?

3.75" stroke pistons w/a THICK head gasket! lol

That shows the "weight" that saying you have a "stroker 383" has- Chevy could have built it w/ a 3.75" stroke, called it a 377 or whatever- but they choose to go w/the extra stroke w/a standard bore 4" block just to call it a "383".

 

OK i have a question about putting a 383 crank in a 350 block.
what rods do you use and what piston?
i have people telling me that if i put the crank in i have to use the 6" rod but use diff. pistons but i if do that it will put the compression back where i started and did not gane anything.

so i guess my question is what are the advantages of putting a 383 crank in a 350 and what rods and pistons do you run

thanks guys

Let me help you out a little. First of all, a longer or shorter rod does not affect static compression ratio as many people think. There are 5 volumes that determine SCR, combustion chamber volume, cylinder volume, piston crown volume, piston deck height volume and head gasket volume.

When planning any motor combination, you must figure out the "stack" of parts you will use. A SBC block is ~9.025" from the center of the main bearing bore to the flat deck where the heads bolt on, so you must use parts that come close to that dimension. The radius of the 3.750" crank is 1.875", so we'll let that be a constant.

If we add a 5.565" rod to the constant, we have a partial stack of 7.44", so if we want to wind up with a stack somewhere around 9.000", then we would choose a piston with a compression height of 1.560". (1.875" + 5.565" + 1.560" = 9.000")

If we chose to use a 5.7" rod, we would have to use a piston with somewhere close to a 1.425" compression height (1.875" + 5.7 + 1.425" = 9.000")

If we chose to use a 6.000" rod, we would have to use a piston with somewhere close to a 1.125" compression height (1.875" + 6.000" + 1.125" = 9.000")

Many builders will then cut the block decks for a zero deck (piston crown exactly even with the block decks with the piston at top dead center) and use a 0.039"/0.040" thickness head gasket to set the squish thus aiding the motor in running on pump gas with a reasonable static compression ratio and a reasonable camshaft.