ls build advise
 

I am currently building an 05 LS 4.8L engine to put into a 76 Camaro and I am using heads with the 243 casting # and an LS6 intake. Well last week I was given the lower portion of a supercharger off an 2010 CTS-V. Is it worth me scrapping the LS6 intake and using the supercharger instead. Is it worth the build. Any advise, opinion or guidance would be helpful. Thanks

The LSA blower manifold will not work with 243 heads. The LSA has square port heads, the 243 heads are cathedral ports.

Not only that, you can't put the Rect port heads on a small bore engine. OP, you might want to re-evaluate the build.

I saw someone has the rectangle port heads for the small bore motors. Can't remember who though.

Mast did have some but I don't believe they make them anymore.

I read on another forum that you can fit rectangle port heads on a small bore motor if you run smaller intake valves. Understand that I read that somewhere, I have no proof that it works.

Where would the benefit be? Massive flowing heads with little valves. You couldn't take advantage of them. I would suggest a killer set of LS1/LS2 heads.

Found them.

http://www.racingheadservice.com/rhs...r-ls1-ls2html/

those won't work for the OP application

The common "rectangle port" heads are the ones found on LS3, L92 & L99 engines
Some people mistakenly refer to all of the rectangle port castings as "LS3" cylinder heads, that come with huge 2.165" intake valves (LS3 are hollow stem, L92, L99 are solid)

The heads that are in the RHS link are LS7 cylinder heads, for small bore 3.90" -up (LS1 5.7L-up), the 4.8L engine that the OP has is only 3.78" bore

While the LS7 heads are a rectangle port, they are a different size rectangle port as compared to "LS3" cylinder heads (see pic)

You would need to run a LS7 intake manifold with the RHS cyl. heads

hope this clears up any confusion

Jeff