Assume a stock L33 5.3L with CAI, long tubes, and full dual exhaust. Half ton reg cab with 4L60 tranny and 3.73 rear diff gears. How big can you go cam wise before killing MPG? Or maybe I should ask, "what cam would yield a nice bump in HP without killing fuel eco?" I understand that driving with my foot plastered to the floor will have an adverse effect. Just looking for something that will mpg well when driven semi-civil.

 

Probably something around a 208/212 on a 114/5 with some "high" .570" valve lift would do nicely. Don't forget a set of springs to match the cam. Where do you want this extra HP? Or is it torque in a certain area or all over the power-band you're looking for? Maybe talk to "Ed" @ FTI.

 

Was hoping to get by with the stock springs. Heads on the motor are the same as LS2 vette heads. The springs on the vette version are good to .550. I haven't been able to find any info on the stock L33 springs. I was hoping to find gains from the bottom end on up. Maybe something a little bigger like a 218/222 112lsa with lift in the .550 range. Compression ratio on the motor is around 10:1.

 

To improve driveability, increase power, and keep fuel economy in mind, I'd suggest trying to find a cam to improve torque rather than horsepower. I don't think you're looking to rev it to the moon are you?

Keep with low duration, 8 degree split, and don't go over .551 lift. Vinci's Ultra Torque cam comes to mind.

210/218 LIFT .551/.551 LSA 116, "ULTRA TORQUE", POWER RANGE 1500 TO 5800, PROVIDES VERY HIGH TORQUE GAINS, GREAT FUEL ECONOMY & POWER, LIGHT THUMPY IDLE. (copied from VHP website).

 

I ran the 217/223 549/549 113lsa from lunati and was getting 20mpg on fwy. Now on the 222/226 I get 18.5-19.5.. and although thesprings are good for 550 just put ls6 yel i say low springs on.. I have 4.10s... I say lunati cam part 60513 I believe ..

 

Thanks, that's the kind of experiences I am looking for. I don't think the 215/227 116lsa blower cam in my previous truck hurt mpg. It would get 16 mpg in mostly highway running. That was a 6.0L with a 4L80E behind it. The 219/231 cam in my vette does adversely effect mileage. I have a pretty good handle on what to do for a 6.0L. I'm hoping for quite a bit better with the high compression L33/4L60 combo.

I don't mind a rougher than stock idle. Some top end pull would be nice too.

 

I milled my heads..030 and the power got so much better.. if ur not planning on buying a converter don't go any higher then 217/223.. that cam had nice top end compares to the 212/218.. my 222/226 is way better up on top but I'm now on a 3600 converter to make up for the low end loss... mill ur heads get some longtubes and intake and get a tune... ull b super happy

 

Compression is already 10:1 on the aluminum block L33. You're saying go higher than that?

 

Yes sir 10.5:1 Here ... truck loves it and so do I.. lol it just improves ur torque..

 

And you're in Cali running on 91 octane?