Pull-off 5.3L heads can be found on the forums for under $100 shipped. What about getting a set of 5.3L heads worked on while you drive the vehicle and do a head swap once the shop has their way with them? 241/853 heads are practically the same head in every way as the 5.3L head, except with 66.66cc chambers and 2" intake valves. All this means is the LS1 heads will start to pull away from the 5.3L heads after 4-5000 rpm, and the gain will be minimal...at least not worth the cost of new head gaskets, head bolts and all the labor involved.

I'd mill the heads .020", 2" intake valves stuffed in with new valve seats cut, new intake and exhaust seals and call it a day after a little port matching and polishing. Ask your machinist what he or she thinks is necessary for your goals. You'd be sitting with a head designed for about 9.7:1 compression that can outflow all LS1 style heads and probably flow better than virgin 243's.

 

whats the flow of 243 compared to the 317 or whatever is in the LQ4 or are they similar?

i have some 243s from my car that might be a nice bolt on for my truck.

btw you should be able to find stock 243s for a few hundred bucks.

 

The more that I keep looking in to this, the more I would like to just get a an extra set of 799 or 852 heads. I have found a lot online for about $80-100 a piece. I would replace the seals of course and just port and clean up them up. Where would be a good place to get some intake and exhaust valves. I would like the intake to be about 2.00 and exhaust to be about 1.57. Does anyone know of anyone that does a good job. I am not worried about time because I would want them good. I don't believe in rushing someone. I like my stuff to be done right the first time. If it takes two months, then it just takes two months. Or can anyone one do it for me. I do not have access to do all this nor the time right now. I would just need someone to do the porting. I will clean up the head myself. Unless they just really wanted to. Any opinions here???

 

Talk to Richard at WCCH (sponsor, link to the right) >>>> He is extrememly knowledgable and will point you in the right direction. tdrumm got a set of StageI heads for his 5.3 and was more than pleased with them. I have a set of StageII 317's sitting on a shelf waiting to get bolted to my LQ9 if I ever get the funds to finish the project (donations welcome lol). When I got the heads from WCCH, Richard spent an extended amount of time on the phone with me, answered all of my questions, and we even bullshat about other stuff that was performance and performance business related...I almost forgot that I was ordering a product lol. I highly recommend them

About the perimeter vs. center bolt heads, that's exactly what the are. Early LS1's had the valve cover bolts around the perimiter of the head, while the 99 and up (I think), have the bolts down the center of the valve cover. Your truck has center bolt

 

yep. pinch some extra pennies and do a mod that will make a real difference.

 

or do the 6.0 AND heads and cam lol.

The 243s flow slightly better than the 317s from the factory (like 4-5cfm difference at .600"), so no reason to go with the more expensive 243s over the 317s.

 

Ok. Thanks for the info everyone.