i want to stroke my 350 out to a 383 or a 355 what do i need to do this?

 

355 is a 0.030" overbored 350.
383 is a 0.030" overbored 350 with a 400 crankshaft.

The 400 crank's mains need to be machined down to fit into the 350 block. Cheapest way to build it is to use the 400's crank and con rods with normal 350 pistons. If you're going to waste a 400, providing you can still find one, just to get the crank and rods, just build the 400 instead. The 400 hasn't been a production block since 1979.

You can use longer rods but special pistons need to be used and clearancing needs to be checked. Since the 400 crank is externally balanced, you need the 400's balancer and flexplate/flywheel or an equivalent aftermarket.

Nothing wrong with a short rod stroker plus it's cheaper to build. That's the way they were built for years before the aftermarket started offering good stroker pistons. When I used to have a short rod 383, I ran high 11's at 117 mph in the 1/4.

 

they make 383 cranks with 350mains u can find on ebay cheap u could also find a full assembly ready to go for a good buck. then ur gona spend a nice $ in machine work on the block for boring clearncing

 

I agree, build a 406.

 

Aftermarket stroker cranks are also available in forged steel. All factory 400 cranks are cast.

406 = 400 block bored out 0.030" over. About the most you ever want to go with a factory 400 block is 0.040" over. After that the cylinder walls get pretty thin.