there is no stock setting as all pumps have many bench settings and all respond differently when initially set-up. generally they are pretty close to in the middle. ide personally slide a #10 full forward as it isnt an aggressive plate.

yes you could have tightened up te stock springs but you would have only gained a few extra rpms. my 4ks are shimmed out with stock spacers to get just a little more. the tighter you go the poorer idle quality you will have because you are compressing the big idle spring more than what it should be. again go initial click plus 6. this in normally as tight as you can phsically go. i use a quarter with a noth filed out to set the tension on the 4 sided nut that CLICKS when it rolls to the next flat. go as tight as you can go you wont be upset with the outcome. just done break an ear off the quarter you just filed or you will be sad...

a 160 pump has nothing to do with the engine itself. they are the same engines. the 215 pumps can support more HP but this is because of camshaft design for the most part. a 160 175 and 180 pump can be built to do absolutly whatever you want mild to wild. leave it a 160 until you want 800+ HP then get out your wallet.

 

LOL, yeah 800+ ... Your gonna need a bigger wallet for all that money to fly out of ..