Move engine back

Is it possible? Sure. But you’d need to fabricate new engine and transmission mounts. And then deal with the transmission linkage and/or floor opening depending on your shifter and transmission type. And then deal with the exhaust issue (header clearance), distributor to firewall and wiper motor clearance, and even the valve cover to firewall and valve cover to bulkhead connector clearance.

Depending on how far you move it some of those may be bigger issues than others. Seems like a lot of trouble for very little gain. What is the clearance issue in the front?