I'm too cheap to spend 10,000$ on a new hull, and my current hull is very slow (lowe 1852 w/ 35 GDSD) at 22 mph EMPTY. Having said that, spending the money to get my motor modded out is cheaper and more practical for me to get the extra speed I want. I know a better hull is the best mod but I don't want to go there yet.
What kind of horsepower can I expect from heads, cam, roller rockers, pushrods, bps duals, and mikuni 42mm for the motor, and I'm assuming I'd need to run a 12+ pitch prop (the stock 3 blade is a little less than 12 I think). Anyones experience and input is greatly appreciated!
The motor is a 2011 35 GDSD w/ CDI and my budget is something less than 2.5k.

1. Are you doing the work yourself? If not 2.5k won't be enough. I have a 35 GDSD on an 18'44'' GD boat. Top speed stock was 27. I added a MM exaust, iron mountain heads, black death intake, Mikuni carb, bps, cam and had the heads and intake ported and polished by SETX. Speed went up to around 33. The extra speed was cool but the most noticed difference was load carrying. 22 sounds awefully low. What rpm are you running at? Also I didn't change props. Still using the original 3 blade turning 4450. Hope that helps.

your motor prolly has burnt valves...

with the mods listed you would need the high rev coils...


do heads and exhaust IMO

Where did you get quoted 10k for a hull?

Yes I'd be doing the work myself. I run 3600rpm trimmed all the way down with a new prop. 3800-4000 with the worn out one I've got now (only have 40 hours on the motor I'm kinda bummed I'm in need of a new prop already)
Also, 10k for a hull in Alaska was for an excel 1854 from a dealer (camo, with trailer). I don't know how I'd have burnt valves the motor is hardly broken in and has performed like this since it was brand new... I guess that's an even better excuse to get new heads.

The valves prolly were not set right from the get go. My buddy is a mechanic on small engines and has seen burnt valves in as little as 7 hours. My cousin had to just get new heads and valves at 36 hrs. I'd bring it to a service center while it's under warranty

Interesting about the valves being so sloppy so fast that seems pretty disappointing. Probably explains the crappy idle and occasional random dying of the motor. I don't run long distances trimmed down I just get baseline RPMs from there because its an easy position to duplicate. Having said that, I get my best performance at around 3800 with a new prop, I trim it up till I find that sweet spot with whatever load I've got. I'd like to be able to run at that same depth at a higher RPM...
So, since I'm not too interested in fixing valves or getting warranty work done, would the mods listed above push me over 50 hp? That's kind of my goal I'd like to get to... I'd like to put the motor together and take it to the local race shop for fine tuning and dyno. When I make a 40 mile run at <20mph loaded I'm wishing for some HP for sure!

Before spending the $$, set your valve lash (easy to do & only takes a few minutes), & make sure your govenor is set at 4200-4300. If these are off, it will hurt your top end. If you still aren't satisfied, the mods you listed, plus BPS pistons & c-rods will put you a lil over the 50 hp mark.

What's the optimum valve lash for the 35? 004?

.004-.006

Why do you want to do mods without figuring out the problem first?

Because its winter time and I don't have anything better to do... I don't think a tuned stock motor is going to get me another 10 mph anyway.

All those mods won't get you anywhere near 10mph if your hull is a dog.

I have the GDSD 35 non cdi with the GDSD 1660 boat. at 40 hours depending on the stuff you are running your prop is probably shot. I can tell you here in Florida I have to put a new prop on every season, and I am running the GD 3 blade and have had great luck with it. My motor has 168 hours on it and its a 2005, I have owned it since new. When new with just me it would run 28-29 top speed, but with 4 decent sized guys and hunting gear we could run around 24 in shallow water, but as soon as we hit deep water the speed would drop to around 17-19. Last year I put the MM exhaust, Iron mountain heads, and 42mm mikuni carb, and new prop. Got all the performance parts from SETX, Keith has a package I think around the 1500.00 range. I did all the work myself, and I do not consider myself a motor head but I am mechanical, in about 4 hours. I can now run 30-31 with just myself, actually the problem I have at running that speed with the GD is the motor wants to keep popping out of the water, I have tried to bend the tabs up but that does not seem to help much. Here is the big gain, last week I ran 25-26 in deep water with 3 big guys 250+ 70 lb dog, boat has the mudbuddy quick flip blind (35-50 lbs) extra 27 series battery 2 doz dekes, 3 guns 3 blind bags, and a carsten pintail (100 lbs) , and a 16 foot old town canoe (100 lbs). Where I hunt it is a no motor zone but you have to get there by boat, cross a deep lake, its about a 30 min run from the ramp, so I had a rack built to put the extra boats on. I would think you would get similar performance even with the hull you have if you shaved a few of the items mentioned above, like the extra boats. If you are looking for 30 + loaded, I don't think that will happen with the GDSD, I could be wrong, I would like to here some input from other GDSD owners as their experience with having the motor pop out of the water at that speed, I have even thought of welding a weight to back to help keep it down. Oh by the way my RPM's were about the same as yours around 3800-3900 trimmed, now I run about 4300, just shy of bumping my rev limiter.