"Adding displacement is the quickest, easiest, and often least expensive way to increase power throughout the entire rpm band, especially in the lower rpm range where torque is king." -- John Lingenfelter on modifying small block Chevys.

 

i'd do a 383 for these reasons
you can run a bigger cam and still be driveable/emissions, more torque, and more room to grow(better heads later)

now i'd do a 355 if your trying to stay in a budget... using stock rods, crank and after market pistons. you will be able to do that for way cheaper then a 383

 

How can you use the same heads when the heads off a stock short block are the incorrect size for a 396? Maybe I am missing something here, but the heads would at least have to be modified to work wouldn't they? And if so, that alone can make up for the extra HP. I should have worded my statement slightly different regaurdless. A 383 over a 355 will add MOSTLY more torque, and yes probably a few more HP, but mostly torque. Bigger upgrade to a 396 would be even a larger difference.

 

No, there's no "fitment" issues. They may not flow well enough to feed the engine to its best potential but they will work. The deck doesn't change on a 396, will get decked most likely, but that only affects height and piston to valve clearance (which should always be checked)

 

he's probably had his lt1 stroked to 396

 

Gotcha. I have no problem admitting to when I just don't know. Thats why I like these forums. Thanks for the info.

 

it was a 396 cubic inch LT1. as in 4.030" bore and 3.875" stroke crank. a 383 is a 4.030 bore and a 3.75" stroke crank.