Next Performance Modification, 90 ZR!

[ZR1@LAST]

Hi all,
I would like opinions on my next bang for the buck (without breaking the bank ) I should look into?
My 1990 ZR1 has the following modifications:
Fitted with Watson headers & ceramic coated, mated to a B&B 3" Exhaust. Idles nice and quite, with excellent oil pressure & zero noises. Good power, estimated @ just over 400 crank due to the headers and custom chip calibration. Drive train DANA 44 equipped with 3:92 gears.

I do not want to do any head work. I know I am comparing two very different cars, but on my 86 Grand National, cold air induction really helped. I do not want to cut the front license plate area to induct cold air into the engine.

Please give me any thoughts you all have?

Thanks,
Jeff
90 ZR1