Just got my worked over 5.3 truck heads in from ET heads and let me tell you a full CNC port and polish job is bad azz!!

They bench flowed 328 on exhaust and 235 on intake which is one of the highest on the market through some of the research I have done. They have 1.65 exhaust and 2.08 intake valves in too. .30 worth of milling and decking and 62cc chambers. Too bad I can't get a better intake manifold to help these heads out.

Now I still wonder what they will make bolted on top of a 224/224 112lsa LS1.? Long tubes and UPD should run pretty good... then I will throw 100 pills to it

 

what are these going on? that intake flow is sick...what lift is it at? the exhaust is decent also....got any price info for ET?

 

Those heads should work great with a 6.0,but the valves would be to big for a 5.3 with it's smaller bore.Good looking heads.

 

They are my 5.3 heads off my old motor, and they are going on an LS1 5.7 out of an 01 vett.

 

Very cool!

My GTP S2+ heads from 3yrs ago flowed 317 intake 220 exhaust and yours far surpased them! Congrats!!!

 

how much did they charge to p&p the heads.

 

So I guess that means you are going NA,with about 11:1 compression and big *** cam.I think I'd go with more cam than a 224/224 and look into a T-Rex from Thunder.Then look into a direct port nitrous like a Noszle system.

 

He might not need the bigger cam. The heads I have were packaged with a 223/.589/112 cam The original owner made 437rwhp/419rwtq with typical bolt-ons and no dyno tricks.

 

Yes I am going to be NA. I am pretty sure I don't have enough stall for a cam that huge. Also I think there are a few drivability issues with that cam. Also the 224 is a very proven cam as it has been around for awhile.

The t-rex doesn't make ANY more power than the 224 until something like 6300 as far as all the graphs I have looked at. ~ Even then it is like 20rwhp difference. I (parish and I) am going to tune this cam and heads in and then see what it makes first. Then maybe a direct port setup shortly after

 

Hell even on an LS1 bored motor of ~3.9" that 2.08" valve is WAY too big. That's better for at least a 4.060" over motor. I'd have stuck with a 2" maybe a 2.02" intake on the LS1 motor.

Alas it's your truck but those heads seem a bit extreme even for a 224/224 cam. It's gonna pull like a ***** from ~3500 to the shift point, but don't expect much down low.