if you spin the timeing chain on a 390 do tne valves hit the pistons?

 

I don't see how that could happen. So long as your valve springs are in good shape. It would run very bad or not at all.

 

With a bigger cam and higher compression pistons it can definitely happen. I'm not sure about the stock truck 390s but it is likely that they can touch if it were slipped to just the right position.

 

Brain lapse...

Sean's right. I guess if you're far enough off on the cam to crank timing, there could be valve to piston clearance issues. Especially for high lift cams and high compression pistons.

I wonder if any cam/crank timing position would result in clearance issues on a stock truck FE motor? They are low compression with valve reliefs in the pistons.

 

i know they will on a stock 302.i would think they would on most v8,s.