Originally Posted by KCS

243's have a better port, which the 241's/853's can't achieve unless you weld/add material onto the short turn. This helps make power where 241's/853's couldn't. For a street car, it probably doesn't even matter much anyways. On a real N/A race engine, this is absolutely crucial.

As far as ported 241's vs. as cast 243's, it all depends on who ported them. You could have some "head porter" with his "competition valvejob" put a head so far out in left field for the intended combination, you would be better off with stock castings. TEA seems to be a reputable shop, so I'd bet their 241's would be a good investment.

Originally Posted by 02*C5

A lot of people think that the 243 is such a superb head, because they keep the valves, and they don't have to do anything else. That is wrong, if you did a good P&P job on those things with the right cam the HP gains are profoundly different specially if you go with the Ferrea valves (hollow). The 241's will end up choking the engine but again it depends on the set up and package. All equal the 243's will out flow and out power the 241's by a wide margin. Some of those 243's if done by a good shop will flow close to heads like FRP's @ half the price.

Originally Posted by Paint_It_Black

ummm.. wtf are you talking about??

longer runners for higher rpms? I know those TPI engines were real high rpm screamers.. and someone better tell F1 they're doing it wrong! (study a bit on wave tuning, you're completely backwards)

longer runners in an LS6 head? they have the same entry and same exit locations, does the port do a loop-de-loop inside the head or something?

lol this kind of stuff is what you get when you build a car through the advice of an internet forum.. you get mismatched or sometimes just bad parts, claiming to make 450rwhp but goes out and can't break 120 in the 1/4.