I developed a head gasket leak after changing the lower intake manifold. I started by changing both heads, and used the “dual torque” method alternating between heads and lower intake, when all reassembled I had a lower intake manifold leak left rear. It was a gasket issue so I replaced one piece gasket with two piece Fel Pro. Now I have developed a leak in the right front. It is where the head mates to the block. Should I re- torque the head bolts?

 

Welcome to the forum

No, you can't reuse 4.0l head bolts so can't re-torque them

I assume a 1990-2000 4.0l OHV engine?

You do not need to install lower intake with heads, you can but doesn't help anything, install lower intake after heads are done, and add lock-tite to the lower intake bolt threads
These bolts only use 14ft/lb so tend to loosen up which causes an air leak, or coolant leak at the corner of lower intake


As for the head leak, I assume coolant not a "blown head gasket" cylinder leak

ot sure why that would happen?

Did you have the heads surfaced while they were off?

Why did you change the head gaskets in the first place?

 

Original maintenance was for fouling cylinder 4. Decided to replace both heads with rebuilt ones. Don’t want to remove head bolts just tighten them again. Coolant is leaking from the head gasket at the block as I refill coolant. Engine has not been ran since maintenance began.
I initial reassembly I had a leak when refilling in the lower intake gasket. After replacing this leak developed. I can only assume removing the lower loosened the head enough for it to leak. The area is much lower than the initial leak.

 

No, heads are separate, any work on lower intake manifold won't effect either head/block seal

Once the head bolts have been turned the final 90deg they are stretched out, if you loosen them then they won't un-stretch and if you tighten them more they will stretch more....and when you do start and run the engine it will heat up and the head metal will expand, as it should, and then the bolts will stretch even more but thats planned on, if you over-tighten them they could over stretch and snap, this is also why you can't re-use these types of TTY bolts

Not sure what to tell you on this, a gravity leak at the head block seal usually means some debris was left on the head, block or gasket when reassembled