Kodiak544

If I went with a new set of heads from PRC say the ls6 would I have to check for valve lash or just tighten the rockers up and rotate the motor and torque to 22lbs in the firing order? The heads on the now have 6,000 miles on them 2001 gmc Sierra.

FFDP

iTrader: (2)

It would be easier and far less money to buy some stock 243/799 cylinder heads and swap those on.

If you aren't going to put a cam in the motor to make those $1,000+ cylinder worth it, then why spend the money. Dollar to horsepower gain wouldn't be worth it. You'll be further ahead with just some stock 243/799 heads.

ezdaar

iTrader: (1)

He is right.

Kodiak544

Ok thanks but how would it be easier?

Kodiak544

I forgot to say it has a 212/218 cam and longtubes just wondering what to do with installation process

FFDP

iTrader: (2)

Easier on the pocket book. Take off 243/799 heads can be had to less than half the price of those LS6 CNC heads.

Kodiak544

I got a price of 500 for labor thought that was pretty good price just wondering how to install them. I have installed knock sensor s before so I know that much.

bobfig

with the 243/799 you would have to mill them some to get the compression the same as stock or you will be loosing some. should be around $50 to do that but just a heads up on that. as for $500 install thats pretty good imo.


also it's 22 in/lbs for the rockers and if you mill and even if you don't you will need to check push rod length.

Kodiak544

Thanks guys what kind of head gaskets do I need it's a 99 gm rebuilt engine.

TPayne03/5.3

Hey I just finished up my head swap a few weeks ago. 243 heads will be your cheaper route. I got mine for $450 shipped from a guy from the Facebook group called lsx parts for sale. They pop up for sale on there pretty often. Then you will need a machine shop to mill your heads .030 to get your compression up. I had cometic send me .040 thick gaskets that they cut to match my cylinder bore think they cut them to 3.810 in. With this gasket and .030 milled off your heads your compression will be higher than factory. I had my machine shop do a valve job while they had them. I also put new LS7 style lifters in and new lifter trays while I had it tore down. Running great so far, they are a good compliment to my cam. I did all the work, install wise and I spent around $1800. It's not cheap. I'm sure others have done it cheaper. I videod it and put it on my youtube channel called SilveradoNtheStang https://m.youtube.com/watch?v=oxzZTLrlt3Y check it out. You will 100% need to measure for pushrod length. Mine ended up being 7.325 in pushrods and my valve train is pretty quiet. If you've replaced knock sensors you might could do your heads. Good luck man.