5.7 350 Camshaft

X2
As mentioned above, makes 330HP with decent heads. If it's an old TBI truck motor you'll need to put on Vortec or at least TPI heads for those numbers. The Corvette ones were aluminum. It's more the heads that made the LT1 and LT4 hotter engines, but they won't work on any other SBC because of the reverse waterflow in the LT1/4 blocks. Not talking about water pumps, the whole engine was reverse water flow. While still using the basic SBC rotating assembly and roller lifter valvetrain.
If your engine has a flat tappet cam these cams won't work unless the block has the proper machining for a roller cam and lifters. The distributor gear must also be for a roller camshaft or the cam will eat a non melonized gear quickly. Those cams do have a fuel pump lobe but you'll need a block that is roller ready and drilled for a fuel pump. I believe some 638 blocks have both. Some were even 4 bolt. Great base for a stroker 383 or 406.
If it's not roller ready call Summit and ask what flat tappet cam will work best for your intended use.

Don't order any cam until you absolutely verify which lifters you have.
The easiest way to do this would be to remove a valve cover and one pushrod. Count the turns as you loosen the rocker arm and retighten exactly the same amount will save needing to adjust that valve when you reinstall the pushrod. Stick a borescope down the hole and look at the lifters. You can get one for your phone on ebay for under $10.
You won't be able to see the bottom of the lifter but will be able to see if there are roller lifter retainers or not.
The tin spider and the figure 8 shaped retainers around the lifters will not be there with a flat tappet cam.