Just wondering what you might think this combo will produce.
It's a 1990 454 Magnum that was build by previous owner, this is what I know.
Pistons are L-2465 (9.6:1) from what I find with 119cc heads. Rectangular port
Cam is a Crane 134241
Crane roller rockers
Merc dual plane high rise intake
HP500 carb (Blue) and has the original staggered jetting.
Gil manifolds and risers.
Stock ignition.
Haven't had but one ride before winter set in. Currently spinning a Bravo 1 26P

Would any changes on the outside at this point be of any benefit?
Maybe an intake change?

Prob around 450hp would be my guess. Cam is similar to the stock cam in the 420HP 454 Merc, as is the rest, aside from the higher compression .

425-450 hp. Its pretty much a Merc 420 with a little more compression.

Old threads with same cam and similar build and dyno specs
mild cam upgrades on 365 hp 454
Paging Griff

Griff, sounds to me like you built this engine except for pistons

Very similar. I only did a complete top end on mine. I picked up about 400rpms and 4 mph in a 24 Outlaw which translates to a solid 60 hp gain.
I gave the info about what I did to the other guy and he did a full build and dynoed it and confirmed my hp estimate.
Your CR bump will prob give you another 10-20 hp.