zippy

Yes they were. These are the heads.
http://texas-speed.com/shop/item.asp?itemid=84&catid=20
It is very commong for the LS1 and LS6 guys to run those heads. The 243's are a very good cylinder head with how well they flow. I'm a big fan of those cylinder heads. The 5.3L only has around 9.5:1 compression though and unless you plan to spray big on it or run boost you might as well go for any compression gain that you can get. The L33 and NNBS 5.3L's running the 243/799 heads all make excellent power from the better heads, more cam, and higher compression due to using the pistons originally designed for the 4.8L. Other than the slight cost difference the choices are fairly obvious. Ported 5.3L heads will outflow 243's and give you more compression.

As for the intake, I'd look for an intake from an 07' and newer 4.8L/5.3L truck and put a 90mm throttle body on it. They are fairly available from those swapping to a Magnacharger. The best one is going to be an intake from a Flex Fuel 5.3L as they will have the larger injectors as part of the deal. The last one I did was a non-Flex Fuel truck and had the larger injectors also, but it doesn't seem to be a sure thing unless it's a Flex Fuel truck.

Jermoslin

iTrader: (2)

If you mill say .030" do you have to get shorter pushrods and will the intake ports be mismatched.

00ChevyScott

iTrader: (10)

they have those rules for a reason.

Jermoslin

iTrader: (2)

Deleate to follow rules

Mangled03gmc

iTrader: (95)

Do the 243's, also the 92's won't work on your engine....

00ChevyScott

iTrader: (10)

we've established that

and I think I'm gonna send my heads to WCCH sometime next year

dlt76028

iTrader: (13)

can i swap a 6.0 in place of my 4.8???

A Low Dime

iTrader: (13)

What cam should i put in my 5.3? Also, what converter would work best since I will be towing a boat and racing every weekend at the track against camaros?

lucky77

iTrader: (4)

ported- 243's with a valve job.. should do the job....