340 Cam Size

508 cam is a **** cam for daily driving.
I'd do as wymrider said with checking the compression.... but so that you can transfer your 340 cam and lifters into it without detonation issues...lol

508 is not a great low end cam, you'll want something with less than 270 degrees if you really wanna daily drive with an automatic transmission. 4 spd is a diff story...