The Stovebolt Site Forums The Shop Area Engine Shop Installing cam in my 5.7 Liter Vortec

Getting ready to put the finishing touches on my engine. I'm using a 5.7 Liter Vortec 30 over, flat top pistons, vortec heads and the original roller setup with an LT1 cam. Which of the following would be recommended?
1-Retard 4 Deg.
2-Advance 4 Deg.
3-Heads up
I'm running a 700r4 transmission with a 373 posi rear end. I like to get on it occasionally, but would drive to and from shows also. Any input with be appreciated.

It's my understanding that advancing the cam 4 degrees brings the torque and horsepower curves down toward the bottom end, and retarding cam timing pushes them up to the higher RPM ranges. For a truck I would think you would want it advanced. However (there's a "however" here!) It is considered to be inadvisable to mix advancing/retarding the cam with a special grind. The aftermarket cams take into account the timing, so by changing it you are defeating the design of the cam. You need to know what the grind of the LT1 is supposed to do. Personally, I would think it is ground with neutral or retarded timing for higher RPM performance. I think I would set it neutral and drive it a while, then take it back apart and advance it, and see if I like it better.

With that said, I put a 4 degree cam advance and replaced the stock 1:5 rockers with 1:6 on my 5.7 TBI '89, in conjunction with changing the ECM PROM and going to larger exhaust and intake. It took it from dog to nice driver (in a Suburban with 3.08 rear gears). The PROM and the rockers were the only things that I wasn't replacing as maintenance, so with the additional money I spent on an upgraded exhaust and intake instead of stock, I spent maybe $200.00 making this Suburban a much nicer driver. (The low end torque is really nice for towing and it will put you in your seat coming off the line.)

I used a 350,'87 suburban 4 bolt block with vortec heads and a 99 EFI setup. Contrare to popular beliefs, if the block has cam retainer,and drilled for roller guides it doesn't meen it will take a roller cam! If tappet bores are counter bored you wind up with no oil pressure and starved lifters. Hard lesson to learn, now has flat tappet hyd lifters and cam. Zeke

I would do what the cam card recommends, provided you bought your cam for your specific application, which I presume is a truck.
Scott

Thanks everyone for the input. Good point on the grind. I've heard there is a special timing cover, with access to make cam changes without much trouble. I will go heads up at first and see how I like it and then advance 4 deg to see what that does.