I did a search and did not find much info on anyone using these engines. Since My wife and I own a Late Model GM Performance Shop, I build alot of High Hp LS engines and was thinking about swapping out my big blocks for 2 LSX 427's with F1R Prochargers, however, not sure about the outdrives /bellhousings mating up. Has anyone done this swap before or is it more trouble than it is worth.

Chris

We've thought about that as well, seems like a great platform for sure. I think Raylar is doing some LS stuff. I am thinking about doing an LS in my 71 Trans AM. Is this the kind of thing you do? I did an L98 TPI in my 71 Camaro several years ago when they were the latest greatest. All i can say is I'll never run a carb again.


How would you handle an 02 sensor in a marine engine? Is it still possible to get the system to function in closed/open loop without it?

We can do conversions. We have a few, and also completed one that someone else started but could not finished. You can tune the PCM in SD so that it dosn't use the 02 sensors. Basicly run off the VE table and not allowing the PCM to make fueling corrections.
The PCM dosn't use the 02 sensors except for cruising around town, once WOT the 02 Sensors are not in use.It reverts to the MAF table and if no MAF it use's the VE Table. Sorry for the long write, but no , you do not have to have the 02 Sensors.

Chris

I just finished a ls for my boat ,the bellhousing fit whit minor changes and the mercruiser bravo coupler bolts right on a ls7 flywheel ! so no big deal !
I run dry exhaust whit o2 sensors .
just on the dyno have 550 hp @ 6200 and 535 ftlbs of tq from 4000 to 5500 rpm it;s a stroked ls2 whit ls3 heads and all forged internals .

Really.. This is great to know. I had heard you can run dry exhaust but wasnt sure. This is good to know. I can see 2 LSX427 with prochargers in my future.

Chris

i think what he ment by dry exhaust is their is still wate going through the headers but dry at the tip and dumping the water else where.

Oh.. Ok. I had someone tell me that you can run water close to the end where the exhaust runs thru to hull to keep it cool but you did not have to go thru the entire header.. Not sure.

Your right I have watercooled headers and tails ,but dump the water elsewhere due to the reversion the cam makes ,if you dónt cool them it become to hot in the engine room

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JIMKID Has a LS7 Powered 30' Skater. He'll be a really good judge of what the LS based engines need for the marine HI-PO market.