I have a 02 Avalanche Z-71 with the 5.3 and 3.73 gears. On friday my STS turbo with GT-35 and methanol injection is going on. I am going to go with a Fuddle converter next payday, either a 3000 or 3200 stall. I was wondering how beneficial a cam swap would be and which type of cam to go with. I want to do the SLP 1.85 rockers, valve springs, and pushrods at the same time as well. The other thing I have to worry about is that I live in California, so I need it to pass smog, not necessarily be smog legal, but just be able to pass. Down the road will be a gear swap to either 4.10 or 4.56. My tire size is 305/40R22.

 

You don't need a gear swap. It will haul a$$ with the 3.73s. The lower gears will load the turbo and it willl be fine. The stall will take care of any lag. 212/218 would work well. Skip the 1.85s if you do a cam. Just do the 918 springs and hardened push rods.

 

Why do you say to skip the 1.85 rockers? Is that just a mod for keeping the stock cam?

 

You got it.

 

Do you have a 3/4 ton or did you do a 4L80e swap. If you did a swap I would appreciate some info on that.

 

we have used several, and some better than others. We had great results from an '03 LS6 cam, 650 on a mildly built motor. We recently used a LPE GT-7, 208 230 .556.546 on a 121. Perfect idle. At 9psi it made 506/623.
We have tried the reverse split cams too. A 226 220 on a 115. Mid range seemed to really pick up, but no better peak numbers.
If you want smooth idle, stock, LS6, GT-2+3, GT-7.

 

I would go to Cam Motion's web site and fill out their Cam Request form. When they respond, come back here and tell us what cam they recommended, I'm sure you aren't the only one interested in a cam for that type of setup.

 

I submitted a request to cam motion today, I will let you all know what they say.

 

You will need to drill new holes in the flex plate fot the tq conv to mount to. Cut and remount the mounting plate on the cross member. Order a wiring harness to adapt to the stock tranny harness. New drive shaft yoke. Possibly shorten the drive shaft. A 4l80e tune from hptuners. I think that covers it.

 

Here is what they e-mailed me.
RECOMMENDATION
Grind Number X2121-2021-15+4
Duration (intake/exaust) 216°/210°
Lift (intake/exaust) .547/.544
Lobe Center Separation 115°
Intake Centerline 111°

Any opinions on this recommendation?
What are the benefits of a reverse split cam?