4.8redchev

My engine builder for my dragster said he would look at my heads and see if he could port and polish any....would this help? my truck has the 4.8L im not sure if those heads are even worth doin it atleast he said he would clean them up as much as he could and if i wanted he would port them for me

goshawk23

these heads aren't like what most people are used to when it comes to cleaning them up. every bit helps but make sure he gets some info on these heads before he touches them. they are easily rendered useless in the wrong hands. page BigKid, as for he just went through his heads and did some nice stuff to them.

Jason 98 TA

iTrader: (4)

Definately be careful!! It's not a old school small block/big block. You might consider Patriot 5.3l heads if your wanting a good flowing set of heads. $1295 for heads With 2.02 intake & 1.57 exhaust valves complete with double springs!! Then you could sell your stock heads

02Reaper

iTrader: (2)

Dont you think those valve sizes are a little bit to big for a 3.78" bore? Just about all of you aftermarket guys think we are running a 3.9" bore like the 5.7's or the 4.00" bore like the 6.0. Im beginning to wonder if most of you even know what you are talking about at all.

Sport Side

iTrader: (6)

i agree on the valve issue. it seems that 2.02 intake 1.57 exhaust is the common valve size most ls1 guys go to after a head swap.not all, but alot. wouldn't it be overdoing it to stick those size valves on a 325ci motor?

BigKID

iTrader: (5)

I just got finished working my own heads and I think they turned out nice. Basicly all I did was blend in the valve seats to the bowls, smoothed out the valve guides and cleaned up the ports and polished the combustion chambers. There is a post with pics I made a few weeks back when I finished the first one. I got some more yesterday that I can post up as well. I have to get them to the machine shop this week to have them milled then I will be putting them on weekend after next.

02Reaper

iTrader: (2)

Yeah, post them up. How about a write up on what to remove, comparing them to some stock pictures?

BigKID

iTrader: (5)

I wish I would have taken some before and during pics for you guys but unfortunately I didnt. I want to see how mine pan out before I start telling everyone else what to do.
btw... here is the other thread with my first set of pics. https://ls1tech.com/forums/showthrea...highlight=head I will get the other ones up when I get a chance

ktmrider

4.8Red, there are some good publications out on cleaning up the heads on the LSx platforms. Any knowledgable shop can help you out with minor work. Like stated above, be careful if the shop is not familiar with the LSx heads. They can definitely do more harm than good.
Also mentioned is the limits on the 4.8/5.3 bore. The 3.78" bore will cause "valve shielding" which negates any flow increases due to the valves being too close to the cylinder walls.
Last, the head work would probably not be realized without a cam upgrade. Lift is lift, no matter how much intake charge is available. There are a couple of guys sticking with the 4.8L and getting great results. Post a "Help needed" in this section regarding H/C combos and options. Good luck!