I am finally have some money in my pocket and I'm ready to upgrade my current boat or purchase something different. The problem that I have is, I really like my boat and everything in Nebraska is way over my price range. Everything I like is between 40,000 and 90,000 witch is not in my budget. I am currently running a 2002 Rivermaster with rod lockers and a 425 Cadillac DD 72" Q. I have done lots of digging on Cadillac motors and reductions, leading me with my particular engine not very buildable in this application, now if I had a 472/500 they sell way more parts for those engines. Your thoughts? So my thought is a 6.0L LS with a reduction and new prop. I'm figuring 15,000$ for my build. I am a certified welder and can fabricate for this application. I have been told that an LQ9 is a good choice with either a 2 to 1 or 2.37? and I would figure a 3 blade Sensenich would work? I'm guessing the next power plant will be between 300 and 400 hp. All your thought on my build are appreciated.
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looking for advice
- Thread starter Roweboat
- Start date
terrible ted
Well-known member
Once you have the motor and the gear, they can advise on the prop for you.
SWAMPHUNTER45
Well-known member
LS with a 2.55 would be my pick some might suggest 2.68
There is a recipe for a hot 425 but for the money you can’t beat the LS options.
There is a recipe for a hot 425 but for the money you can’t beat the LS options.
90chevy396
Well-known member
Just went from a direct drive fiberglass board to a pull out 5.3ls and a 2.68 with a 3 blade 80”R and I will tell you this even a junk yard pull out with Holley terminator x bone stock is a world of difference
Went from a 13’6” laser hull 6’8” wide with a built 455 Buick to a 16’X8’ aluminum hull with a stock 5.3 with 2.68 rotator and even with new boat being over 800lbs heavier it will drag that Buick boat backwards on dry ground.
One problem I had with the Holley is the map sensor was not in the handheld to program into the tune so I had a bad stumble that I had to figure out but once I seen the map sensor data and simple change in the software by puting micro as cars into lap top and changing the map sensor graph couldn’t be happier with the build being a true budget build. Other than having minor influence from a buddy on the software any good mechanically knowledgeable guy can get it all worked out.
Again if you want to go big their is a few key shops to look into for performance products for this type of build just do your research and find out which path will be best for you.
If you are building an engine above stock then once you have an idea what kind of power your running and what RPM you want to turn it call your preferred prop manufacturer and get their suggestions of ratio and prop for your setup
Went from a 13’6” laser hull 6’8” wide with a built 455 Buick to a 16’X8’ aluminum hull with a stock 5.3 with 2.68 rotator and even with new boat being over 800lbs heavier it will drag that Buick boat backwards on dry ground.
One problem I had with the Holley is the map sensor was not in the handheld to program into the tune so I had a bad stumble that I had to figure out but once I seen the map sensor data and simple change in the software by puting micro as cars into lap top and changing the map sensor graph couldn’t be happier with the build being a true budget build. Other than having minor influence from a buddy on the software any good mechanically knowledgeable guy can get it all worked out.
Again if you want to go big their is a few key shops to look into for performance products for this type of build just do your research and find out which path will be best for you.
If you are building an engine above stock then once you have an idea what kind of power your running and what RPM you want to turn it call your preferred prop manufacturer and get their suggestions of ratio and prop for your setup
Slidin Gator
Well-known member
The 6.0 Iron truck motor is definitely your best bang for buck when hitting the junkyard circuit these days. They are cheap, plentiful and make power easy.
If you are planning to run a carburetor, the Cathedral port Gen III motors are best. If you are planning injection, the Cathedral port works, particularly if you are just jacking up a stock motor a bit. For max power on injection, look for rectangular port gen IV.
Here is some info I pulled together to compare all the different LS options.
If you want to spend a bit more money and save some weight, here is the short list of aluminum block LS options.
If you are planning to run a carburetor, the Cathedral port Gen III motors are best. If you are planning injection, the Cathedral port works, particularly if you are just jacking up a stock motor a bit. For max power on injection, look for rectangular port gen IV.
Here is some info I pulled together to compare all the different LS options.
If you want to spend a bit more money and save some weight, here is the short list of aluminum block LS options.
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Aeon
Well-known member
Do not do a ls with a 2/1 reduction. 2.55 at a min. Especially a low displacement lss.
When I first got my ls3 I had a 2/1 belt box and it had trouble spinning the 78 falcon 3 blade. Fast forward to the new boat I built with the same motor. This time I put a 2.55 ox and 82" jx 3blade pitched past the 2 mark and spinning like crazy massive change in thrust
When I first got my ls3 I had a 2/1 belt box and it had trouble spinning the 78 falcon 3 blade. Fast forward to the new boat I built with the same motor. This time I put a 2.55 ox and 82" jx 3blade pitched past the 2 mark and spinning like crazy massive change in thrust
90chevy396
Well-known member
Digginfool should be able to chime in on choice and experience with 2.55 & 2.68 he tried several gears on his ls boat. Right now I am spinning a 80” 3 blade R at 2 mark 5850 with a 2.68 and 5.3
Cruise is right around 3500
Cruise is right around 3500
One Eyed Gator
Well-known member
I run a 6.0 with holley efi TBSS intake stock gm 36lb injectors with and ASA cam (road racing cam) Gearbox is 2.55 with 81.5" 3 blade R, would like to try a 2.68.
Maybe makes 400-425hp runs good for what it is. Runs good for what it is budget pull-out build.
LQ9 has slightly more compression than a LQ4. If you going to run a carb and are looking for a budget type build a set of good (not cracked) 706 heads will bump the compression and help keep the plenum velocity up with the small runner.
Used a set of 706's and had the 2.00" intake valve installed from the 317 on the 6.0 That with the ASA cam engine runs very strong and is now 3 years old. 706's also have a small runner which helps plenum velocity if you're running a carb.
If you know which vehicle the motor you want is in try www.car-parts.com great junkyard search engine
Maybe makes 400-425hp runs good for what it is. Runs good for what it is budget pull-out build.
LQ9 has slightly more compression than a LQ4. If you going to run a carb and are looking for a budget type build a set of good (not cracked) 706 heads will bump the compression and help keep the plenum velocity up with the small runner.
Used a set of 706's and had the 2.00" intake valve installed from the 317 on the 6.0 That with the ASA cam engine runs very strong and is now 3 years old. 706's also have a small runner which helps plenum velocity if you're running a carb.
If you know which vehicle the motor you want is in try www.car-parts.com great junkyard search engine
digginfool
Well-known member
The manufacturer that owes me the gearbox still has not come through on his promises so, unfortunately, I don't have anything to offer.