those are pretty good engines with the aftermarket blocks and high volume
oil pump. i would install some afr205 heads with the 58cc chamber which will increase compression about a half point, maybe more, make sure to get the hydraulic springs, maybe have to change pushrods for length, but check. could increase rocker ratio if the heads will allow but wouldn't sweat this, the cam is pretty good for the cubic inches, wouldn't be worth the change for the gain imo. would check the advance/retard on the cam, my crate 351 was installed 2 degrees retarded, you can advance up to around 4 depending on what you feel like. the pistons should have the eyebrows for the bigger valves, my 351 did for the afr185's i installed but the intake valves on these are slightly smaller.
after i got all that sorted out i'd install a lightweight flywheel clutch, the as issued on mine was 40+ lbs., i installed a 17 lb'er and there is quite a bit of difference on perceived hp. depends on what you want to do, drag racing i wouldn't do this.
buy those heads above and a clutch/flywheel and you'd be out for around $2k, pretty good.