[Captainfab]

I would suggest the '73 and newer motor mounts as well. The frame brackets from a '73 and up C20 will work better in these older trucks as the frames are closer in height than the '73 and up C10's. The '68-'71 big block brackets and mounts will work as well as the one year only '72 mounts. However they are typically $150-$200 for a setup. Plus from what I've read the motor mounts themselves for the '68-'71 aren't available new. So you would be stuck with finding good used ones.

The long tube headers for the '73 and up will work just fine unless you're laying frame or super low. You will also need to trim the top flange of the frame for the big block clearance. If you can find a '68 and newer frame, or complete truck, you will see what I mean if you compare them.