sand man

your the first person that I read about that changes the heads from rectangular port to cathedral , why ?

these are some serious numbers , but why didnt you get the L92's CNCed ?

iamkeniff

iTrader: (16)

He took the heads off of his H/C 5.3

youngone2011

Does he still have the 5.3 :0 I want to buy it !!! Lol

TXsilverado

iTrader: (19)

awesome numbers. why not go speed density and get that MAF out of the way completely? my last tune was speed density and the drivability was actually better in my case. get on the track and set a new best. the time in your sig kills me. ok 60' nice mph but 12.80 with that mph and 60' just doesnt sit right with me. it should have been low 12's.

i've heard of several well known head porters say that they would take a well ported cathedral head over the square port heads. not sure what there reasoning is but i'm sure theres a reason that all of the aftermarket castings are still cathedral.

1slow01Z71

iTrader: (36)

They haven't really needed an aftermarket square port head because the factory castings can flow so much. If you want more than the L92s you can step up to the LS7 heads which flow north of 400cfm in the right hands. Allpro now has an aftermarket square port casting that Richard at WCCH has done an awesome job with as well as MAST with some of their own castings.

My simpleton, non-expert opinion is the cathedral heads are more responsive. I will be ditching the square ports on my L76 in favor of some WCCH 317s. For as much power as this motor is suppose to make it just feels dead below 3500 and will only get worse with a cam.

If you're willing to run the converter and gear I don't think you can beat a ported square port head when it comes to bang-to-the-buck if you're mainly interested in track times. My truck is a heavy pig and I need to keep good power in the 2000rpm range for decent mileage and towing so the big square port heads aren't as good of a fit for me.

02_Orange_D1SC

iTrader: (30)

damn 34RWHP gain i two just did one of these and i can say its worth the money IMO i def noticed a pretty big gain just by the seat of my pants i haven't had it on the dyno since i put it on but i put down 390RWHP with s stock 78mm truck intake I'm hoping for 420 to 430 with the LSXRT.

whats the specs on your cam?

skeet

iTrader: (18)

do a 5" if you can, if not mistaken the 102 is 4.750 at the mouth, 4.500 in the back, i found a single 4 was a restriction the gain in Kpa speaks for itself.. with a great tuner SD is your friend

RickLowpez

yeah i went with the cathederal heads cause they were left over from my 5.3 also i already had a cam for this set up so it was the best bang for the buck for me.i will be working with cal speed on the tune and some changes in the near future thanks on the comments keeps me motivated to keep modding and to keep on truckn

RickLowpez

when u had ur 6.0 what size intake tube size where u running/

rjwz28

102mm is just a hair over four inches (4"=101.6mm)