ScorpioV8

For a L33 5.3, stock 799 heads, which would give the best gas mileage and drivability? Outright power not the main issue.

GM ASA .525/.525, 228/236 110 LSA
LS6 2002-4 .551/.547 204/218 117 LSA

I'd assume BOTH would need LS6 springs, but will the stock pushrods and rockers be fine?

Any thoughts

Thanks

Gareth

garygnu

the smaller cam will get better gas mileage.but alot of people like the power and sound of the bigger cam.stock rockers will work just fine.I would recommend better push rods,especially if you are a m6.

ScorpioV8

By M6 does that imply the pushrods are 6 mm diameter? I've had a look under the rocker covers and these are bigger than that - maybe my engine has had some upgrades? It came out of a 2005 Silverado 1500 and was RWD only - GM4L60E. The WWW says they never made a RWD only with an L33. It also had huge downpipes, bigger diameter than the cast iron exhaust, welded straight onto the cats.
Best I get the front cover off and have a look at the number on the cam....

Thanks

Gareth

intenseblue

iTrader: (1)

He was referring to stick shift, which you shouldn't be. Definately change pushrods and springs if you change the cam.

theevette

iTrader: (2)

Ive got the ls6 now its a good setup and get 26-28mpg with a 6 speed in the vette. Its has the stock ls6 springs and pushrods and has 120k on it with no issues. Sounds and drives as good as my 5.3 truck. Asa cam has a good lope and gm used it for scca racing I beleive. The asa should make more power, look at the duration, its the one I would choose, like the nasty cam sound and can live with drivability issue which shouldnt be bad with a tune

2nd Gen Fl 'bird

iTrader: (13)

The ASA cam has a little thump to it, look at the duration. Also, power will peak higher. I don't think that is too good for MPG, still not a bad cam. LS6 cam is pretty much dead smooth but, more lift obviously. Will most likely have to spin the hell out of the 5.3 to make use of the power band with both. If you're on the budget side of things try a stock LS1 cam(.500/.500) the 5.3 supposedly responds very well to it. Keep your heads stock at the same time.

intenseblue

iTrader: (1)

With that setup I would definately go custom.

A.R. Shale Targa

iTrader: (2)

X2^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
GM cams are good pieces but aftermarket sticks unleash more power by
improved lobe designs. Arguably both more power and better mileage
Call some of the vendors....they may even have a perfect shelf cam/spring
package for you

garygnu

be careful down shifting with stock gm push rods ,they can bend.also consider the gm hot cam.