one other thing I have read a ton about is that the stock rocker arm is prone to throwing our needle bearings. Comp cams makes a trunion upgrade kit to fit the stock rocker arms. Most people are using this kit rather than running aftermarket arms. I figure for the cost its cheap insurance.

On a side note about any of the ls engines. so anyone who's ever had one of these motors knows they consume oil.... usually about a quart every oil change. So, I have been doing a lot of reading and some discovering on my engine build. I would highly recomend installing an oil catch can between the pcv and the intake. I have never seen so much oil built up inside of an intake in my life. it felt like 36 grit sand paper. i soaked my intake for 2 days in purple power and water then another day and a half in dawn ultra and water. i then used a scrub brush to clean out the runners. I had all kinds of stuff come out of that thing. Most everyone on the ls forums are running catch cans and they say it stops their oil consumption.

If you are going to spend the money, you might as well just buy real roller rockers. They really aren't that much money.

I was going to but the trunions are 130 and real roller rockers are 400-500. Most of the LS guys are simply running the trunions. The stockers are actually very light and very strong, other than the factory needle bearing design. If I was going to build a high rpm screamer i probably would swap the rockers. I'm not trying to cut corners just spending the money where it will do the most good. I could easily drop an extra 1500 on a fast intake and roller rockers and gain maybe 3 mph? The motor itself is mostly stock. other than the valve train, and bigger injectors. I'm going to take a guess at 450 Hp off this build and thats 200 hp over the stock 350 mag that I took out. The wife is being good to me not saying how much I can spend or not spend...lol She said just make sure its reliable. the boat made it back to the dock less than 50% of the time we took it out...lol I should have listened to my gut when I got the boat and gone through the motor...

Honestly, unless the cam is big, run the stockers with a trunion upgrade, way lighter easier to keep the valve train stable. I have a set of jessels on my ls7 and I would swap back but the valves I have are not stock height and the geometry would be way off. Unless its a solid roller with shaft rockers the the stockers with the trunion are the best bet imo. I don't really like any of the non shaft options.

sounds like you have a pretty mean ls7 in something. In all honesty I probably could have just dropped a stock lq4 motor in the boat and gotten the needed parts to make it mount and been done pretty cheap. Other than the exhaust... i dont want to scare anyone away talking massive money to make the swap happen. I just happen to want to get more performane out of it. I save a ton of money repinning my ecu myself. most places want 400-700 for a harness. I even went as far as to put nylon braided sleeves over the wires and heat shrink the ends of the sleeve. that took forever by the way but looks killer.




I laided it all out the way I wanted it then had to take it apart to fit the sleeve onto it... well worth it in my book. I'll be doing all my wiring in the engine room the same way. after pulling out the factory harness I can see several areas where it was rubbing on something and had worn the wire down to copper.

Do you guys think the 6.0 would have enough power and torque to replace a set of stock 340 HP big blocks in a 10,000 lb deep v offshore boat without going slower ?????? JOHN SR

I'll be putting down north of 450 HP with just a cam change, tune and headers. ( I may be conservative on this). These motors can lay down well over 700 HP without forced induction. I know of at least one person who wanted to do twin ls to replace the bbc. Also in the skater forum there is a 24' skater with twin 5.3's hitting I think 105 mph. In my opionon yes I can say twin mild build ls engines will smoke 340 bb any day. shave 300 lbs off each motor and pump them up to 500 HP each, yeah I believe you will love the results. Also the fuel consumption on the new ls engines is far superior to that of the old sbc and bbc.

As big a fan as I am of the LS platform... a boat that heavy really needs the torque of more cubic inches. Just my 2 cents.

The LS engine will respond to almost anything and make HP/TQ by accident. And as far as oil consuption, I know the 5.3's had an issue at first, but my LQ4 in my '03 HD hasn't used a drop, and has towed alot. Everyones experiences may vary.