procharged97

trying to figure out what size cam i should put in my truck. its a 97 chevy k1500 vortec 350 5.7L procharged. feels like im running out of cam at the top end and the values are beginning to float. any ideas?

southern_chevy

iTrader: (9)

any lt1 cam i believe will work in it but you will have to change out springs and you still cant go very big on lift with those heads. You can get different locks and gain a little lift back.

1Bear

iTrader: (1)

While you can physically use a LT1/LT4 cam in your Vortec 5.7L, if it is a factory cam you have will possibly have to cut down the cam gear dowel pin, as they protrude .620” from the end of the cam to engage the opti-spark on some models. The L98/Vortec 5.7L cams will have the dowel pin set at .30” +/- .01” like any other small-block. Typically, aftermarket cams and the GM Hot Cam for the LT1/LT4 motors have the dowel pin extended out, but can be tapped back in for use in the older motors.

A decent choice if you do decide to do a cam swap “of course there are others” from Comp for an application such as yours is a 210/220 .500”/.510” 114. It’s rated for 1400 to 5400 rpm, but that is in a normally aspirated combination and will have extended capabilities being supercharged. You don’t have to worry about spinning it too anyway, as the black box PCM in the Vortec trucks will not allow you to spin it over 5800 rpm.

You will need to change the valve-springs and unless you pulled the heads to machine down the guides for extra clearance and to install something like a metal bodied Viton seal or a posi-stop Teflon seal to use in conjunction with standard small-block type valve-springs and retainers, which probably wouldn’t be a bad thing as the heads probably need freshened up anyways, you will need to swap to LS style beehive springs.

Standard small-block spring height is set up at 1.750” and the typical beehive spring height such as used in the LS type motors is 1.800”. To run LS1 style Beehives in a SBC designed with 11/32" valve stems, you will need to use a hybrid retainer. Comp makes such a retainer Part # 787-16. Also to get the installed height of 1.800" you will need a +0.50" steel lock/keeper. If you install the LS style beehives such as the Comp 915 at 1.750”, you will do 2 things, one you will increase the spring pressure over what the spring is typically rated for, and two you will cut down on the amount of lift you can actually run by .050”.

I used this same configuration on other trucks and have verified that I would have been able to run .530" lift before contact was made. Of course every combination is different and will have to be verified.

southern_chevy

iTrader: (9)

I would say if you go thru all that you might as well put a 411 PCM in it. Lot better I think as lextech and I were the first to have one up and running. Higher rev limiter, more tuning options, most say they run smoother and better with them. And if you want much boost without all the add on injectors you will be swapping to a different intake manifold since the factory poppet injectors wont flow enough. The marine intake has been a fav since it looks stock and is not to bad to swap in.

If you do the cam swap I believe I have some +.050 locks new in box if your interested

the_husk

I too have a L31 truck.

Why not just call Comp and get a custom grind? Tell them what's done to the truck, and what you want out of the cam.

Edit: Try to keep it under .525"

james8997

im running .536 on stock heads with beehives