Does anybody have any recommendations for props ,with 496 ho

What year hull? Assuming 2002+ with those motors?

If that's the case labbed 30p Bravo I's likely.

2002 , what kind of speed can be expected

From what others have said with the 2002+ hulls, 70 GPS probably any day and 72-74 then conditions are right. If not labbed props, likely 28p stock bravos.

I have an early 2000 380 with strakes trimmed back to 34", tired 1000 hour 502MPI with a hotter tune, running pretty much consistent 70 on GPS with heavy weekender loads and fuel. 30p stock bravo's at 5000-5100 rpm. Stock 28p bravos could bounce off the raised limiters at 5300 rpm. Could get more out of it but it takes a long time to gain those last few MPH, not pushing the tired motors that long. My prop slip is horrible around 24% though. If I wasn't planning major motor upgrades, I'd probably try Hydromotive P-5X props or the new larger diameter BBlades 4-blade props.

I currently have 2002 Vyper with fresh 500s . We are looking at 2002 38 with 496s, thinking of maybe swapping the motors . The vyper might be easier to sell with 496s. Any suggestions ?

I would for sure do the swap if it were me!!!!!! Most with that newer hull and 500's are solid 75mph and 78-80 when the stars align. Besides, 500's leave the door open to much more upgrades in the future, and you already know the history and health of the 500's. That Vyper will still run dang good with the 496 HO.

Kind of what I was thinking . It's just nice to know what other people think to .

Absolutely swap the 500's into the 38. Trust me, it's a big heavy boat, it'll be worth it.

Good prop would be a stock 28" bravo 1. Better would be a labbed 28" bravo 1 by Bblades, adding 1" of pitch.