[LTb1ow]

Start by doing a pressure test of cooling system, and then verify that a HG is leaking.

If it is, personally I would do both HG but thats me. Its doable without taking the motor out, but since you don't strip it down to hot tank the block you will never have it completely clean. You can try to fix it, and cycle oil out of the engine frequently till you are confident its cleaned up. If you caught it soon enough and don't have a bent rod I would say just R&R HG is fine.

When you do pull the heads, check each piston at TDC to make sure you didn't shorten anything. I would recommend ARP head bolts and a quality HG set. Get everything as clean as possible and have your heads checked for straightness. Toss a straight edge on the block as well. Stock head bolts call for TTY so you will need an angle torque wrench, or use ARP which use a straight torque spec.

If you can follow bolt torque sequences and can work in odd angles its most def doable.