ally wet block or dry block?

hi all!
i would like some advice on the potential use of an aluminum KB wedge wet block to replace my current setup which is a production 383 cast iron block,totally filled,with a 3/4 in thick girdle plate to stiffen the bottom end,used dry.
this is in a blown injected alcohol engine,currently making roughly 1000 hp on a conservative setup(hat injected only,8.71 HH blower,22% OD) in a small 100 wb FUNNYCAR)
why switch you may ask?
because that block is a boat anchor,versus the KB,so i would save a lot of weight(no more girdle plate,easier access to bottom end).
the max hp we would like to make out of this KB block would be 1500 HP,so would it handle them "as is" or would i have to add filler anyway?
ditto with heads:i m currently running "poor quality" ally wet heads that are filled,and have the opportunity to get "good quality" B1 heads,wet,that i would use dry.
so any input would be appreciated before i spend my hard earned cash...
thanks
cyril