New member here and also long time viewer/fan. i have a factory lq4 and am curious to see if anyone has swapped 243/799 heads from the 317's. is it a direct swap? any real gains to be made from just the head swap, a tune, and short tubes? i dont want to do long tubes yet, kinda building up to that, already have the short tubes for free. head gasket upgrade to withstand the higher compression? i use this pickup as my daily driver and am mainly below 2000 rpm,s but want a little more power for the weekend. i already run 91 octane for current tune. just dont know if the 1100 dollar swap would be worth it. been a tech for five years, turning wrenches for ten. i realize i can pick up used heads for cheaper but dont want to mess with it. i want it to be reliable and not have to worry about little things happening like a broken valve spring or a head gasket job within a few years. thanks!

 

You should install a cam while your at it and use the 706/862 heads they are proven to make more tq and hp

 

not wanting to do a cam swap as not enough funds

 

Yeah thats fine id still recommend 706 defiantly

 

Watch Richard Holdeners videos

 

 

I don't think that will make your compression to high and up to you if your not looking for more performance

 

 

They flow more but don't make more power according to his test

 

The only benefit from 243s is compression. You get 3-4% per point. I have an lq4 and milled mine, granted I have cheap costco 93 octane here in Texas. Find yourself a used cam, low lift so you can use cheap LS6 springs, and it will get you way more power than a head swap. Even a stock LS6 would be a decent upgrade over the weak LQ4 one. Trust me. It's worth it. Running a BTR Stage 3 truck cam.

Mine stock dyno'd 265 hp. With stock heads and intake adding cam and headers and cheap e fans got me to 325 hp. Since then I added TBSS and those ported and milled 243s. Still not quite the gain I felt getting the cam and headers.

 

Yeah whats your goals hp tq wise or do you just have those heads laying around and curious about runing them? id say any good stage one cam with some pac 1218s /1219s would be good for any build or just use those 243s over ur 317s

 

Throw them on, you'll get a little bump in power everywhere.

If you're buying new heads though I would recommend buying used ones and sending them off to be gone through, mild port work, a little mill and new springs. The cost may come out close to the same as buying new heads and you'll essentially have new heads. If nothing else used heads, take to machine shop to have them inspected thoroughly, slight mill, valve job and bowl blend and you'll gain a lot of power there and spend about the same money.

You could do used heads and have them decked and just have new stock springs installed for now, new LS6 springs are only $70 and you can use drop in truck cams with those springs. Drop in truck cam is $400 and you can toss that in later and keep the valve springs, push rods, and timing chain.

And yes it's a direct swap, take old heads off put new heads on.

Don't go with the cometic head gaskets mentioned above, they are expensive and .027 put's the quench at around .020 and that's too tight IMO. WS6 store is now selling .047 head gaskets for around $50 if I recall correctly and those will give you a tiny bump in compression and are cheap.


https://ls1tech.com/forums/generatio...d-gaskets.html

 

Or you can use elgin stag 1 or 2 for 250 pac 1218s will support a lot of lift and power for 110 and worked 706s or 243s will put you around 350 with a lot of torque id go with 706s tho

 

I'd spend the extra $50 or so for a truck cam and have more low end since it's a daily driver truck, be better with a stock stall too.

 

ordered a set of heads, had them for a month now, havent had a chance to install them. doing knock sensors, lifter cover gasket, etc. one more dumb question. installing the 706 on the 6.0, do i need different length push rods or adjustable rockers to do this if i'm keeping the factory camshaft?

 

Should be the same but like everyone says its best to check.

 

 

I was wondering how the 706/862 heads would do on a 6.0. The 706 head testing was done using a 5.3 engine.

 

 

Did you use a low lift cam?