Those Square port heads are HUGE, you have to run a really big cam and intake to even get those heads to start flowing.

I just got done building my 454 4 Bolt main, Heres the list

.30 over on the block so .30 Over Hyperectectic pistons
.268 comp Marine Cam
Stock cast Oval port heads slightly ported with 427 Corvette valves.
Mellings stock oil pump ( high flow will run the pan dry on high rpms)
Stock port matched intake ( my boat has a covered engine, no room under there)
Heavy valve springs
10 Qt marine pan
Double roller chain
Stock balancer
Stock rods
ARP bolts

I had the Engine built at Bob McKrays performance in Mission Viejo, I didnt touch the thing, Cost me 3000, Estimated 475HP

Hey guys I just had my 454 rebuilt, and wanted to know if I run thermostat in it or leave it wide open without one?

From some Jet boat guys told me to run it wide open, my friend whos a great car guy told me put a thermostat in it or it will never warm up.

Wanted to know what you guys thought since you guys probably know,  Thanks alot.

Its not a marine engine, its a GM performance Crate 454, I know the pics look bad but thats before I cleaned it up some,
Yeah I need to pull the bottom out and should have a machine shop atleast hot tank and hone it.

Thanks for the advice.

okay thanks guys, i will just keep it. im still looking for an engine, i may have on this week but i should have the Tahiti day cruiser ready soon. I heard there nice driving boats and that the day cruiser was a full stringer. cant wait for proving grounds at lake Hodges and then off the AZ to Martinez. Yeah!

Thanks SuperDuty, Yeah the motor mounts are still bolted in the boat, there are four of them. I have the motor in pieces, the crank is shot
its probably a late 80s block, 4 bolt main. Small oval port heads which ive been told are junk. I would like to find a good running stock BBC between 500 to 750 bucks.
I dont want to go big on the first block because I dont know for sure if the pump is okay and if the hull takes on water. It appears to be fine, and I was told that the
pump had been rebuilt by Niel at Performance Marine in Spring Vally CA, and still hasnt been fully broken in, still needs to be greased during operation until broken in.
So thats where im At, Thanks for your input.

Hey everyone, I just got my first boat two days ago. its a 1974 Tahiti, came with a berkely JG pump which supposedly only has 10 hours on it, Jetavator with Hydro place diverter. The upholstery is in great shape and its three tone, the bimini top is new and covers the whole cabin. GT wheel and nice guages, Nice speakers with an amp, wired for subs. It came on a Tandem axle Trailer with good tires. It is set up for a 454 BBC and I think I was given all the marine parts for it, it doesnt have the motor in but I got the old broken one taken apart. I got it for $1000 bucks, did I get a deal? Are Tahitis good boats? are BBC boats a good setup?

Thanks Guys,

heres a link to the boat I bought

http://sandiego.craigslist.org/esd/boa/1721380642.html