Drivability with 13mm
 

How much power and dd change would a 13mm injection pump make.

dd with a 13mm pump is gonna be a smokey hot ride. 12mm pump will make a ton of HP. 800hp on a benched 12mm is do able.

Next question would be what all is done to ip when they are benched. Obviously they are made better and fuel flow would have to be better. But is there any specifics to it to what is actually done

totally depents on how you want the pump set up? cam profiles cc's dv's springs, timing

where is a good place to get it benched? how much does it cost also?

scheid, columbus diesel, heisley machine to name a few.

you can get a pump benched and set up with 5k gsk for 600 bucks or so