As long as you get the marine motor , I dont see a problem with it . Especially for thype of boating you do .

-beerjet-

ya their prices are cheap. but i am not looking for a race boat. i just want something that starts eveytime i take it out.. as long as it will do about 45mph i am fine. i am sick of working on my boat i want to enjoy it a bit.

I know that is how you feel now, but once you have it running reliable THEN you'll wish you had more ponies.  I'm just saying that 2-3K will be adequate and probably not long lived. A quality crate motor is going to run you twice that but will last 10 years even as often as you go to the river. Talk to the people at Speed-O-Motive out by you. Get the parts from them and any reputable machine shop can put together a BBC.

If you go there . Ypu might as well have them put it together . Awsome shop and very knowlegable folks.

-beerjet-

Bear in mind I have never owned a BBC in my life but LS6 or 7 motors can make 400hp/450ftlb with little trouble and with stock(ish) heads. I'm just saying that putting together a motor that will last is going to cost at least a third more than what I saw on those two links you posted. In my old boat that was similar to yours I ran a 400 sbc w/ a corvette cam from around 1978 up until about 5 yrs ago. It still runs, we just don't use it anymore. It had enough HP to once pull up 4 skiers at once out in front of water wheel camp. You can easily spend $1500 just putting Edlebrock heads on. Not sure that is the best use of your money if you are on a budget. Put a quality long block together and you can add to it down the road.
Again, this advice is worth what you paid for it.

I don't know how far from San Diego you are but I know a chevy guy who has worked for crower cams , Ultra Boats and has been a gust engine builder on Overhaulin twice that maybe you should talk to. Give me a PM if you are interested. He works out of his house now but does great work for a really good price.

i am interested. san deigo is not far about an hour from me. anyway i just want something that will not give me any more problems. this motor i have in there now was pro built buy a race shop. i trust these guys work they have built a couple of my motors and i have not had a problem. I only got maybe 10hours on the motor since a complete rebuild. i still dont know the extent of the damage.  i am not even that excited about going down to the river and working on it. i am debating just letting it sit there for another week. i dont know. but yes i am interested in your guy. if you takl to him often. ask how much and how long it would take to run through my 454 and make it bulletproof.

through my 454 and make it bulletproof.

Wrong hobby if you want it bulletproof! 

IF you are look to rebuild it go to total performance it's in santee san diego. He is one of the better in town and STANDS BEHIND HIS WORK!!! great guy, he build my buddy a nasscar motor for his offroad truck, plug in and heat the oil and shit, crazy motor big hp, also have had all of motor done there for jet boat, took all the shop motor there from the boat shop.