Engine Positioning Question

[ManNamedJed]

I have a 71 suburban 4x4. It originally had a 6cyl, but now has a 350.

Since I got it last year I noticed a few odd things - the distributor and air cleaner are really tight with the firewall. I installed a Classic Air AC kit and the hose from the front of the truck to the AC compressor barely reached, whereas the one from the firewall forward to the compressor is extra long.

Then I read that 6cyl and V8 mounts in a different spot on the frame. So I go take a look and sure enough, there are other mount holes about 2" forward from where my motor mounts are.

Is there a reason they didn't reposition things when they did the engine swap? If the engine, and trans and tcase move to the forward spot, will the stock drivelines need replaced? Did Chevy have different driveline lengths for I6 vs V8 vehicles?

I am about to install an HEI dist and new intake, so I'm concerned about clearance.

If I move my engine to the forward position, other than the exhaust, and drivelines, will I run into any other issues? Looks like there is room for the fan.

Thanks!