what would be a good size to scale down a hustler boat? the boat is 49' 6'' x 8' 10''

Depends on what your going to power it by ?
If say 25cc gas .... 1/8 to 1/6 scale.
11cc nitro .... 1/10 to 1/8
7.5cc nitro .... 1/10 to 1/12
3.5cc nitro .... 1/14 to 1/16

JMO tho FWIW

1/13 scale would have it approximately 45". How big do you want it?

for power most likely the rcmk, I have some pics that im going to upload in a little while after i get them to the correct size. If i did my math right the length of 66'' and a width of 11 3/4'' would be a 1/9th scale and 74 1/4'' x width 13 1/4'' would be a 1/8th scale. would the width be fine for the lengths though?

here are a few pics of the boat

Wow! That's a nice boat!

yes it is, i just happen to be driving back my the marina to see if the water is freezing yet and I saw the monster (really thats what hustler boats calls it) and i thought to myself that would be a pretty sweet lookin model boat to build. Id like to build it in wood, do you think its possible?

It sure is. I have been building a much smaller version of this exact boat for a couple years now. I somehow found pics of this boat 4 years ago.
I used a drafting program to scale the hull down then a cnc router to cut out the hull sections. once I had those cut out i used 1/8" basswood to connect the sections. I didn't feel like shelling out $50 for ply from my local hobby shop so i ripped 1 by's down as thin as i could get them then skinned it with those. once i had it skinned i fiberglassed the hull smoothed it out and painted it white. The hull ended up being 42" long, 9.5" wide and the transom height was 5 inches. I had this all done in about 3 months. It would have been faster but i had to fix the schools cnc machine first.
The next part was the hard part. I designed the hull around the 25cc homelite engine i had laying around. I scaled the hull so the engine would just fit in the hull. I placed the engine upside down at a 45 degree angle to reduce the height and the bends in the flex shaft. The engine sticks up a half inch above the deck. With the engine sticking up i couldn't do a cockpit or anything so i just made a smooth top with a large air scoop over the engine to hide it and let large amounts of air in because i haven't figured out how to water cool the engine yet.
The part that has taken me so long to get right is the rudder, drive assembly and radio. My first problem i had to solve here was how to build a strut assembly for the prop. I did this by rolling a flat piece of steel around the bearing i was gonna use for the shaft then welding the tube to a plate that i could bolt to the transom. My second problem was my first rudders were in front of the prop but this caused the boat to roll into the turns and swamp. once i figured that out i move the rudder behind the prop. I also had trouble getting my radio box to stay dry when i flipped it. I couldn't use the tupperware container trick because i had very limited space with such a big engine in that small of boat. I ended up building a wood box between 2 of my hull sections and sloshing around a watered down mixture of silicone to build up a waterproof layer inside the box.
After all this was said and done i had a total of maybe $150 into the boat. Man does it move now with the 25cc engine and a 3" prather prop. I do need to buy a new radio for it since i got it wet so many times it must have a short because it only turns right now. I attached a running pic of my boat. I will probably repaint it this summer and maybe add some sort of graphics.

Beautiful shot!!! I wish it was that pretty were I ran my boat at!!! Really good job on the boat, looks like your patience payed off big time!!!

Yeah. Montana is a Beautiful place.
Last time I drove my boat in that pond in Missoula I was to told there were no gas boats allowed there. I have found a new pond in Butte tough. I just built a new strut and new trim tabs for my boat and now I need to get the motor running great.
Does anybody have any tips on setting the carb? I Have it set for running dry but I cant get it to get to full rpms on the water. I have a Homie Motor with a walbro carb with 2 needles an H and an L. I understand the H is the high speed needle and I am guessing the L is the low needle but how do set them?
Thanks, Teich