ls build advise

[Jr]

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.

[badazz81z28]

Originally Posted by Jr

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.

[71455Formula]

Found them.

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

[jwcarguy]

Originally Posted by 71455Formula

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