KeatonAZ

Are there Budget friendly LSx Exhaust manifolds yet? I wanted to replace my 5.7 SBC with an LSx, most likely the 4.8L. I know i'm going down in displacements but the 4.8L/5.3L make more power than a marine 260 5.7L. plus the fact that i can get EFI out of the deal vs converting my current one to a TBI setup (collected all the parts) The reason I was wanting to go with the 4.8L is they are about ~$300 if i pull it at the junk yard. the 5.3L is ~$550-600. either option sounds good until i look for the exhaust which is looking $1,500+ The other option i was considering was a 1996+ vortec motor so I could use my existing exhaust manifolds, pick up the vortec heads in the process.

LTZCrew

id say thats a smokin deal. id go ls all the way, i was looking at doing thats in my old boat before finding my next 'must have' i was planning on doing a ls2 with ls3 top end and real giving in the go. id do a 5.3 if you go ls. better bang for buck and a TON of early ls1/ls6 stuff with work on the bore size for cheaper over the ls2/3 stuff. along with the weight saved itll be a real rocket, can also carb it for pretty cheap or go tbi style injection like fitech or something like that and cut down on the obd2 style electronics

cheech

First off your going to put a Junkyard LS engine in it. The LSX is specifically a block produced by Chevrolet Performance Parts and a line of crate engines derived from that block.
But anyway, one alternative to exhaust is to go to the link at the end of this, download the 6.0 Parts manual, get the part numbers to manifolds, risers, and associated hardware, and whatnot and Google search.
Just glancing manifolds are $275 and risers about $170 ish. Still not cheap but might be a little shy of the $1500.00
Crusader Engines | Classic

LTZCrew

their is a LSX block yah, but most people call the series a LSX like ltX and what not

forgot about the tow boat stuff, great bang for the buck

HotRodV6

I recently purchased a 78 Scarab S-Type without engines, but has 72C transmissions and TRS drives and originally had 350HP 454's but PO had some 500HP 470's that he pulled to pt into a bigger boat. I bought this boat with the plan to install a couple LS 6.0 LQ4 engines with LSA superchargers and from the beginning was having trouble with finding exhaust i could afford, the CMI and Lighting headers were way out of my budget, and originally i went to pleasure craft to look up some replacement LS 6.0 manifolds and found some around 300 each and 160 for the risers that were cast iron, so looking at about 1800 with shipping for both engines with the best price i could find on the net, then someone in the passion for powerboats group on Facebook pointed me to these aluminum high performance manifolds designed for the 6.0 and 6.2 engines and rated to support 550-600HP.

marine engine depot dot com and look under engine parts and accessories and then exhaust and towards to the bottom of the page you will see them.

at 1050.00 plus shipping for the kit, its about the best deal i found for a kit that can support some horsepower. I called and one drawback is they don't have a provision for an O2 sensor, but i think the risers only have water on the short sides, so im thinking it shouldn't be to hard to weld on a bung for an O2. they sell spacers that only have two water holes that you could add an O2, but they are 300 each for a 3" riser which to me is ridiculous expensive.

mcollinstn

No, MOST people do not call the series LSx, just like most people do not call nitrous oxide "NAWSS".
Some people call things the wrong thing, and then there are whole segments of the population that join them in calling things wrong terminology.

But, sure, if you want to refer to the LS series engines (and that's what they are called) with something like LS(x) LSwhatever LSlessthan3 LSthru7 then that's your prerogative. When I read your post, I was pretty sure you were wanting to drop a 4.8L LSX in there.

Crusader manifolds are (to my knowledge) the least expensive out there right now.