Aluminum is just fine for a low to med hp application, there is no need for a mag bronze or stainless impeller if you dont  have the torque or horse power to turn it.Remember bronze or stainless equals more weight and more rotating mass. Also the cut determines how high you want your motor to turn, from what I understand.

There many benefits to running a stainless steel impeller, not to get too involved, but typically small blocks turn a bunch more RPMs than a big block due to the lack of torque with the shorter stroke and smaller cubes of the mouse.

High RPM is not impeller friendly and can cause some severe cavitation issues which begins to pit the impeller thrust surfaces.

The switch to a stroker is a step in the right direction, the 383 is a tricky mod and can be done right. It will not be AS RPM hungry as the 350.

Try to put some more info together on what you are trying to achieve and see what these peeps come up with...

FWIW I have built a 383 aluminum tunnel and I think we missed the mark.....

GT

there is way to many options when it comes down to buying a new impeller. can someone shine some light on this subject?? is the aluminum imp any good? or would it be a waste of time and money to go that way and i should just buy the stainless impeller? what is the ticket on this??

then the cut..its going to be in a small block application. its a 350 now but will become a 383 stroker next winter. so what cut of impeller should i look into? a b c aa ab q y x z h p?? 

any help is apreciated.

thanks

Modern Aluminum Impellers are good to 450/500 HP , Depending on where this motor "makes power" , my expirience has been that most Small blocks work well with B and BC  cuts Not likley you will need a bronze or stainless  for a SBC Lake boat application  Tom